Multi-speed planetary transmissions with three interconnected gear sets

ABSTRACT

The family of transmissions has a plurality of members that can be utilized in powertrains to provide at least seven forward speed ratios and one reverse speed ratio. The transmission family members include three planetary gear sets having six torque-transmitting mechanisms and a fixed interconnection. Also, one planetary gear member is continuously connected with the transmission housing. The powertrain includes an engine and torque converter that is continuously connected to at least one of the planetary gear members and an output member that is continuously connected with at least one of the planetary gear members. The six torque-transmitting mechanisms provide interconnections between various gear members, the fixed interconnection, the input shaft, the output shaft, and the transmission housing, and are operated in combinations of two to establish at least seven forward speed ratios and at least one reverse speed ratio.

TECHNICAL FIELD

The present invention relates to a family of power transmissions havingthree planetary gear sets that are controlled by six torque-transmittingdevices to provide at least seven forward speed ratios and one reversespeed ratio.

BACKGROUND OF THE INVENTION

Passenger vehicles include a powertrain that is comprised of an engine,multi-speed transmission, and a differential or final drive. Themulti-speed transmission increases the overall operating range of thevehicle by permitting the engine to operate through its torque range anumber of times. The number of forward speed ratios that are availablein the transmission determines the number of times the engine torquerange is repeated. Early automatic transmissions had two speed ranges.This severely limited the overall speed range of the vehicle andtherefore required a relatively large engine that could produce a widespeed and torque range. This resulted in the engine operating at aspecific fuel consumption point during cruising, other than the mostefficient point. Therefore, manually-shifted (countershafttransmissions) were the most popular.

With the advent of three- and four-speed automatic transmissions, theautomatic shifting (planetary gear) transmission increased in popularitywith the motoring public. These transmissions improved the operatingperformance and fuel economy of the vehicle. The increased number ofspeed ratios reduces the step size between ratios and therefore improvesthe shift quality of the transmission by making the ratio interchangessubstantially imperceptible to the operator under normal vehicleacceleration.

It has been suggested that the number of forward speed ratios beincreased to six or more. Six-speed transmissions are disclosed in U.S.Pat. No. 4,070,927 issued to Polak on Jan. 31, 1978; U.S. Pat. No.6,071,208 issued to Koivunen on Jun. 6, 2000; U.S. Pat. No. 5,106,352issued to Lepelletier on Apr. 21, 1992; and U.S. Pat. No. 5,599,251issued to Beim and McCarrick on Feb. 4, 1997.

Six-speed transmissions offer several advantages over four- andfive-speed transmissions, including improved vehicle acceleration andimproved fuel economy. While many trucks employ power transmissions,such as Polak, having six or more forward speed ratios, passenger carsare still manufactured with three- and four-speed automatictransmissions and relatively few five or six-speed devices due to thesize and complexity of these transmissions. The Polak transmissionprovides six forward speed ratios with three planetary gear sets, twoclutches, and three brakes. The Koivunen and Beim patents utilize sixtorque-transmitting devices including four brakes and two clutches toestablish six forward speed ratios and a reverse ratio. The Lepelletierpatent employs three planetary gear sets, three clutches and two brakesto provide six forward speeds. One of the planetary gear sets ispositioned and operated to establish two fixed speed input members forthe remaining two planetary gear sets.

Seven-speed transmissions are disclosed in U.S. Pat. No. 4,709,594 toMaeda; U.S. Pat. No. 6,053,839 to Baldwin et. al.; and U.S. Pat. No.6,083,135 to Baldwin et al. Seven- and eight-speed transmissions providefurther improvements in acceleration and fuel economy over six-speedtransmissions. However, like the six-speed transmissions discussedabove, the development of seven- and eight-speed transmissions has beenprecluded because of complexity, size and cost.

SUMMARY OF THE INVENTION

It is an object of the present invention to provide an improved familyof transmissions having three planetary gear sets controlled to provideat least seven forward speed ratios and one reverse speed ratio.

In one aspect of the present invention, the family of transmissions hasthree planetary gear sets, each of which includes a first, second andthird member, which members may comprise a sun gear, a ring gear, or aplanet carrier assembly member.

In referring to the first, second and third gear sets in thisdescription and in the claims, these sets may be counted “first” to“third” in any order in the drawings (i.e., left to right, right toleft, etc.).

In another aspect of the present invention, each of the planetary gearsets may be of the single pinion-type or of the double pinion-type.

In yet another aspect of the present invention, the first member of thefirst planetary gear set is continuously interconnected to the firstmember of the second planetary gear set and the first member of thethird planetary gear set through an interconnecting member.

In yet another aspect of the present invention, the second member of thefirst planetary gear set is continuously interconnected with astationary member (transmission housing).

In yet a further aspect of the invention, each family memberincorporates an input shaft which is continuously connected with amember of the planetary gear sets and an output shaft which iscontinuously connected with another member of the planetary gear sets.

In still a further aspect of the invention, a first torque-transmittingmechanism, such as a clutch, selectively interconnects a member of thefirst planetary gear set or the interconnecting member with the inputshaft, the output shaft, or a member of the second or third planetarygear set.

In another aspect of the invention, a second torque-transmittingmechanism, such as a clutch, selectively interconnects a member of thesecond planetary gear set or the interconnecting member with the inputshaft, the output shaft or a member of the first or third planetary gearset.

In a still further aspect of the invention, a third torque-transmittingmechanism, such as a clutch, selectively interconnects a member of thethird planetary gear set or the interconnecting member with the inputshaft, the output shaft, or a member of the first or second planetarygear set.

In a still further aspect of the invention, a fourth torque-transmittingmechanism, such as a clutch, selectively interconnects a member of thefirst, second or third planetary gear set with another member of thefirst, second or third planetary gear set. Alternatively, the fourthtorque-transmitting mechanism, such as a brake, selectively connects amember of the first, second of third planetary gear set with astationary member.

In a still further aspect of the invention, a fifth torque-transmittingmechanism, such as a clutch, selectively interconnects a member of thesecond or third planetary gear set or the interconnecting member withanother member of the first, second or third planetary gear set.Alternatively, the fifth torque-transmitting mechanism, such as a brake,selectively connects a member of the first, second or third planetarygear set with the stationary member.

In still another aspect of the invention, a sixth torque-transmittingmechanism, such as a clutch, selectively interconnects a member of thefirst, second or third planetary gear set or the interconnecting memberwith another member of the first, second or third planetary gear set.Alternatively, the sixth torque-transmitting mechanism, such as a brake,selectively connects a member of the first, second or third planetarygear set with the stationary member.

In still another aspect of the invention, the six torque-transmittingmechanisms are selectively engageable in combinations of two to yield atleast seven forward speed ratios and at least one reverse speed ratio.

The above object and other objects, features, and advantages of thepresent invention are readily apparent from the following detaileddescription of the best modes for carrying out the invention when takenin connection with the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1a is a schematic representation of a powertrain including aplanetary transmission incorporating a family member of the presentinvention;

FIG. 1b is a truth table and chart depicting some of the operatingcharacteristics of the powertrain shown in FIG. 1a;

FIG. 2a is a schematic representation of a powertrain having a planetarytransmission incorporating another family member of the presentinvention;

FIG. 2b is a truth table and chart depicting some of the operatingcharacteristics of the powertrain shown in FIG. 2a;

FIG. 3a is a schematic representation of a powertrain having a planetarytransmission incorporating another family member of the presentinvention;

FIG. 3b is a truth table and chart depicting some of the operatingcharacteristics of the powertrain shown in FIG. 3a;

FIG. 4a is a schematic representation of a powertrain having a planetarytransmission incorporating another family member of the presentinvention;

FIG. 4b is a truth table and chart depicting some of the operatingcharacteristics of the powertrain shown in FIG. 4a;

FIG. 5a is a schematic representation of a powertrain having a planetarytransmission incorporating another family member of the presentinvention;

FIG. 5b is a truth table and chart depicting some of the operatingcharacteristics of the powertrain shown in FIG. 5a;

FIG. 6a is a schematic representation of a powertrain having a planetarytransmission incorporating another family member of the presentinvention;

FIG. 6b is a truth table and chart depicting some of the operatingcharacteristics of the powertrain shown in FIG. 6a;

FIG. 7a is a schematic representation of a powertrain having a planetarytransmission incorporating another family member of the presentinvention;

FIG. 7b is a truth table and chart depicting some of the operatingcharacteristics of the powertrain shown in FIG. 7a;

FIG. 8a is a schematic representation of a powertrain having a planetarytransmission incorporating another family member of the presentinvention;

FIG. 8b is a truth table and chart depicting some of the operatingcharacteristics of the powertrain shown in FIG. 8a;

FIG. 9a is a schematic representation of a powertrain having a planetarytransmission incorporating another family member of the presentinvention;

FIG. 9b is a truth table and chart depicting some of the operatingcharacteristics of the powertrain shown in FIG. 9a;

FIG. 10a is a schematic representation of a powertrain having aplanetary transmission incorporating another family member of thepresent invention;

FIG. 10b is a truth table and chart depicting some of the operatingcharacteristics of the powertrain shown in FIG. 10a;

FIG. 11a is a schematic representation of a powertrain having aplanetary transmission incorporating another family member of thepresent invention;

FIG. 11b is a truth table and chart depicting some of the operatingcharacteristics of the powertrain shown in FIG. 11a;

FIG. 12a is a schematic representation of a powertrain having aplanetary transmission incorporating another family member of thepresent invention;

FIG. 12b is a truth table and chart depicting some of the operatingcharacteristics of the powertrain shown in FIG. 12a;

FIG. 13a is a schematic representation of a powertrain having aplanetary transmission incorporating another family member of thepresent invention;

FIG. 13b is a truth table and chart depicting some of the operatingcharacteristics of the powertrain shown in FIG. 13a;

FIG. 14a is a schematic representation of a powertrain having aplanetary transmission incorporating another family member of thepresent invention;

FIG. 14b is a truth table and chart depicting some of the operatingcharacteristics of the powertrain shown in FIG. 14a;

FIG. 15a is a schematic representation of a powertrain having aplanetary transmission incorporating another family member of thepresent invention;

FIG. 15b is a truth table and chart depicting some of the operatingcharacteristics of the powertrain shown in FIG. 15a;

FIG. 16a is a schematic representation of a powertrain having aplanetary transmission incorporating another family member of thepresent invention;

FIG. 16b is a truth table and chart depicting some of the operatingcharacteristics of the powertrain shown in FIG. 16a;

FIG. 17a is a schematic representation of a powertrain having aplanetary transmission incorporating another family member of thepresent invention;

FIG. 17b is a truth table and chart depicting some of the operatingcharacteristics of the powertrain shown in FIG. 17a;

FIG. 18a is a schematic representation of a powertrain having aplanetary transmission incorporating another family member of thepresent invention; and

FIG. 18b is a truth table and chart depicting some of the operatingcharacteristics of the powertrain shown in FIG. 18a.

DESCRIPTION OF THE PREFERRED EMBODIMENT

Referring to the drawings, wherein like characters represent the same orcorresponding parts throughout the several views, there is shown in FIG.1a a powertrain 10 having a conventional engine and torque converter 12,a planetary transmission 14, and a conventional final drive mechanism16.

The planetary transmission 14 includes an input shaft 17 continuouslyconnected with the engine and torque converter 12, a planetary geararrangement 18, and an output shaft 19 continuously connected with thefinal drive mechanism 16. The planetary gear arrangement 18 includesthree planetary gear sets 20, 30 and 40.

The planetary gear set 20 includes a sun gear member 22, a ring gearmember 24, and a planet carrier assembly 26. The planet carrier assembly26 includes a plurality of pinion gears 27 rotatably mounted on acarrier member 29 and disposed in meshing relationship with both the sungear member 22 and the ring gear member 24.

The planetary gear set 30 includes a sun gear member 32, a ring gearmember 34, and a planet carrier assembly member 36. The planet carrierassembly member 36 includes a plurality of pinion gears 37 rotatablymounted on a carrier member 39 and disposed in meshing relationship withboth the sun gear member 32 and the ring gear member 34.

The planetary gear set 40 includes a sun gear member 42, a ring gearmember 44, and a planet carrier assembly member 46. The planet carrierassembly member 46 includes a plurality of pinion gears 47 rotatablymounted on a carrier member 49 and disposed in meshing relationship withboth the sun gear member 42 and the ring gear member 44.

The planetary gear arrangement also includes six torque-transmittingmechanisms 50, 52, 54, 56, 58 and 59. The torque-transmitting mechanisms50, 52, 54 and 56 are rotating-type torque-transmitting mechanisms,commonly termed clutches. The torque-transmitting mechanisms 58 and 59are stationary-type torque-transmitting mechanisms, commonly termedbrakes or reaction clutches.

The input shaft 17 is continuously connected with the sun gear member42, and the output shaft 19 is continuously connected with the ring gearmember 34. The sun gear member 22 is continuously connected with thetransmission housing 60. The planet carrier assembly member 26 iscontinuously connected with the sun gear member 32 and with the ringgear member 44 through the interconnecting member 70.

The ring gear member 24 is selectively connectable with the planetcarrier assembly member 46 through the clutch 50. The ring gear member24 is selectively connectable with the sun gear member 42 through theclutch 52. The planet carrier assembly member 36 is selectivelyconnectable with the planet carrier assembly member 46 through theclutch 54. The planet carrier assembly member 36 is selectivelyconnectable with the sun gear member 42 through the clutch 56. Theplanet carrier assembly member 26 is selectively connectable with thetransmission housing 60 through the brake 58. The planet carrierassembly member 36 is selectively connectable with the transmissionhousing 60 through the brake 59.

As shown in FIG. 1b, and in particular the truth table disclosedtherein, the torque-transmitting mechanisms are selectively engaged incombinations of two to provide eight forward speed ratios and a reversespeed ratio.

The reverse speed ratio is established with the engagement of the clutch52 and the brake 59. The clutch 52 connects the ring gear member 24 withthe sun gear member 42. The brake 59 connects the planet carrierassembly member 36 with the transmission housing 60. The sun gear member22 does not rotate. The planet carrier assembly member 26 rotates at thesame speed as the sun gear member 32 and the ring gear member 44. Thering gear member 24 and sun gear member 42 rotate at the same speed asthe input shaft 17. The planet carrier assembly member 26 rotates at aspeed determined from the speed of the ring gear member 24 and the ringgear/sun gear tooth ratio of the planetary gear set 20. The planetcarrier assembly member 36 does not rotate. The ring gear member 34rotates at the same speed as the output shaft 19. The ring gear member34, and therefore the output shaft 19, rotates at a speed determinedfrom the speed of the sun gear member 32 and the ring gear/sun geartooth ratio of the planetary gear set 30. The numerical value of thereverse speed ratio is determined utilizing the ring gear/sun gear toothratios of the planetary gear sets 20 and 30.

The first forward speed ratio is established with the engagement of theclutch 54 and the brake 59. The clutch 54 connects the planet carrierassembly member 36 to the planet carrier assembly member 46. The brake59 connects the planet carrier assembly member 36 to the transmissionhousing 60. The sun gear member 22 does not rotate. The planet carrierassembly member 26 rotates at the same speed as the sun gear member 32and the ring gear member 44. The planet carrier assembly members 36 and46 do not rotate. The ring gear member 34 rotates at the same speed asthe output shaft 19. The ring gear member 34, and therefore the outputshaft 19, rotates at a speed determined from the speed of the sun gearmember 32 and the ring gear/sun gear tooth ratio of the planetary gearset 30. The sun gear member 42 rotates at the same speed as the inputshaft 17. The ring gear member 44 rotates at a speed determined from thespeed of the sun gear member 42 and the ring gear/sun gear tooth ratioof the planetary gear set 40. The numerical value of the first forwardspeed ratio is determined utilizing the ring gear/sun gear tooth ratiosof the planetary gear sets 30 and 40.

The second forward speed ratio is established with the engagement of theclutch 54 and the brake 58. The clutch 54 connects the planet carrierassembly member 36 to the planet carrier assembly member planet carrierassembly member 46. The brake 58 connects the planet carrier assemblymember 26 to the transmission housing 60. The planetary gear set 20, sungear member 32 and ring gear member 44 do not rotate. The planet carrierassembly member 36 rotates at the same speed as the planet carrierassembly member 46. The ring gear member 34 rotates at the same speed asthe output shaft 19. The ring gear member 34, and therefore the outputshaft 19, rotates at a speed determined from the speed of the planetcarrier assembly member 36 and the ring gear/sun gear tooth ratio of theplanetary gear set 30. The sun gear member 42 rotates at the same speedas the input shaft 17. The planet carrier assembly member 46 rotates ata speed determined from the speed of the sun gear member 42 and the ringgear/sun gear tooth ratio of the planetary gear set 40. The numericalvalue of the second forward speed ratio is determined utilizing the ringgear/sun gear tooth ratios of the planetary gear sets 30 and 40.

The third forward speed ratio is established with the engagement of theclutches 50 and 54. The clutch 50 connects the ring gear member 24 tothe planet carrier assembly member 46. The clutch 54 connects the planetcarrier assembly member 36 to the planet carrier assembly member 46. Thesun gear member 22 does not rotate. The planet carrier assembly member26 rotates at the same speed as the sun gear member 32 and the ring gearmember 44. The ring gear member 24 rotates at the same speed as theplanet carrier assembly members 36 and 46. The planet carrier assemblymember 26 rotates at a speed determined from the speed of the ring gearmember 24 and the ring gear/sun gear tooth ratio of the planetary gearset 20. The ring gear member 34 rotates at the same speed as the outputshaft 19. The ring gear member 34, and therefore the output shaft 19,rotates at a speed determined from the speed of the planet carrierassembly member 36, the speed of the sun gear member 32, and the ringgear/sun gear tooth ratio of the planetary gear set 30. The sun gearmember 42 rotates at the same speed as the input shaft 17. The planetcarrier assembly member 46 rotates at a speed determined from the speedof the ring gear member 44, the speed of the sun gear member 42, and thering gear/sun gear tooth ratio of the planetary gear set 40. Thenumerical value of the third forward speed ratio is determined utilizingthe ring gear/sun gear tooth ratios of the planetary gear sets 20, 30and 40.

The fourth forward speed ratio is established with the engagement of theclutches 52 and 54. The clutch 52 connects the ring gear member 24 tothe sun gear member 42. The clutch 54 connects the planet carrierassembly member 36 to the planet carrier assembly member 46. The sungear member 22 does not rotate. The ring gear member 24 and sun gearmember 42 rotate at the same speed as the input shaft 17. The planetcarrier assembly member 26 rotates at the same speed as the sun gearmember 32 and the ring gear member 44. The planet carrier assemblymember 26 rotates at a speed determined from the speed of the ring gearmember 24 and the ring gear/sun gear tooth ratio of the planetary gearset 20. The ring gear member 34 rotates at the same speed as the outputshaft 19. The planet carrier assembly member 36 rotates at the samespeed as the planet carrier assembly member 46. The ring gear member 34,and therefore the output shaft 19, rotates at a speed determined fromthe speed of the planet carrier assembly member 36, the speed of the sungear member 32, and the ring gear/sun gear tooth ratio of the planetarygear set 30. The planet carrier assembly member 46 rotates at a speeddetermined from the speed of the ring gear member 44, the speed of thesun gear member 42, and the ring gear/sun gear tooth ratio of theplanetary gear set 40. The numerical value of the fourth forward speedratio is determined utilizing the ring gear/sun gear tooth ratios of theplanetary gear sets 20, 30 and 40.

The fifth forward speed ratio is established with the engagement of theclutches 54 and 56. In this configuration, the input shaft 17 isdirectly connected to the output shaft 19. The numerical value of thefifth forward speed ratio is 1.

The sixth forward speed ratio is established with the engagement of theclutches 52 and 56. The clutch 52 connects the ring gear member 24 tothe sun gear member 42. The clutch 56 connects the planet carrierassembly member 36 to the sun gear member 42. The sun gear member 22does not rotate. The planet carrier assembly member 26 rotates at thesame speed as the sun gear member 32 and the ring gear member 44. Thering gear member 24, sun gear member 42 and planet carrier assemblymember 36 rotate at the same speed as the input shaft 17. The planetcarrier assembly member 26 rotates at a speed determined from the speedof the ring gear member 24 and the ring gear/sun gear tooth ratio of theplanetary gear set 20. The ring gear member 34 rotates at the same speedas the output shaft 19. The ring gear member 34, and therefore theoutput shaft 19, rotates at a speed determined from the speed of theplanet carrier assembly member 36, the speed of the sun gear member 32,and the ring gear/sun gear tooth ratio of the planetary gear set 30. Thenumerical value of the sixth forward speed ratio is determined utilizingthe ring gear/sun gear tooth ratios of the planetary gear sets 20 and30.

The seventh forward speed ratio is established with the engagement ofthe clutches 50 and 56. The clutch 50 connects the ring gear member 24to the planet carrier assembly member 46. The clutch 56 connects theplanet carrier assembly member 36 to the sun gear member 42. The sungear member 22 does not rotate. The planet carrier assembly member 26rotates at the same speed as the sun gear member 32 and the ring gearmember 44. The ring gear member 24 rotates at the same speed as theplanet carrier assembly member 46. The planet carrier assembly member 26rotates at a speed determined from the speed of the ring gear member 24and the ring gear/sun gear tooth ratio of the planetary gear set 20. Thering gear member 34 rotates at the same speed as the output shaft 19.The planet carrier assembly member 36 and sun gear member 42 rotate atthe same speed as the input shaft 17. The ring gear member 34, andtherefore the output shaft 19, rotates at a speed determined from thespeed of the planet carrier assembly member 36, the speed of the sungear member 32, and the ring gear/sun gear tooth ratio of the planetarygear set 30. The planet carrier assembly member 46 rotates at a speeddetermined from the speed of the ring gear member 44, the speed of thesun gear member 42, and the ring gear/sun gear tooth ratio of theplanetary gear set 40. The numerical value of the seventh forward speedratio is determined utilizing the ring gear/sun gear tooth ratios of theplanetary gear sets 20, 30 and 40.

The eighth forward speed ratio is established with the engagement of theclutch 56 and the brake 58. The clutch 56 connects the planet carrierassembly member 36 to the sun gear member 42. The brake 58 connects theplanet carrier assembly member 26 to the transmission housing 60. Theplanetary gear set 20, sun gear member 32, and ring gear member 44 donot rotate. The planet carrier assembly member 36 and sun gear member 42rotate at the same speed as the input shaft 17. The ring gear member 34rotates at the same speed as the output shaft 19. The ring gear member34, and therefore the output shaft 19, rotates at a speed determinedfrom the speed of the planet carrier assembly member 36 and the ringgear/sun gear tooth ratio of the planetary gear set 30. The numericalvalue of the eighth forward speed ratio is determined utilizing the ringgear/sun gear tooth ratio of the planetary gear set 30.

As set forth above, the engagement schedule for the torque-transmittingmechanisms is shown in the truth table of FIG. 1b. This truth table alsoprovides an example of speed ratios that are available utilizing thering gear/sun gear tooth ratios given by way of example in FIG. 1b. TheR1/S1 value is the tooth ratio of the planetary gear set 20; the R2/S2value is the tooth ratio of the planetary gear set 30; and the R3/S3value is the tooth ratio of the planetary gear set 40. Also, the chartof FIG. 1b describes the ratio steps that are attained utilizing thesample of tooth ratios given. For example, the step ratio between thefirst and second forward speed ratios is 2.08, while the step ratiobetween the reverse and first forward ratio is −0.55. It can also bereadily determined from the truth table of FIG. 1b that all of thesingle step forward ratio interchanges are of the single transitionvariety, as are the double step forward ratio interchanges.

FIG. 2a shows a powertrain 110 having a conventional engine and torqueconverter 12, a planetary transmission 114, and a conventional finaldrive mechanism 16.

The planetary transmission 114 includes an input shaft 17 continuouslyconnected with the engine and torque converter 12, a planetary geararrangement 118, and an output shaft 19 continuously connected with thefinal drive mechanism 16. The planetary gear arrangement 118 includesthree planetary gear sets 120, 130 and 140.

The planetary gear set 120 includes a sun gear member 122, a ring gearmember 124, and a planet carrier assembly 126. The planet carrierassembly 126 includes a plurality of pinion gears 127 rotatably mountedon a carrier member 129 and disposed in meshing relationship with boththe sun gear member 122 and the ring gear member 124.

The planetary gear set 130 includes a sun gear member 132, a ring gearmember. 134, and a planet carrier assembly member 136. The planetcarrier assembly member 136 includes a plurality of pinion gears 137rotatably mounted on a carrier member 139 and disposed in meshingrelationship with both the sun gear member 132 and the ring gear member134.

The planetary gear set 140 includes a sun gear member 142, a ring gearmember 144, and a planet carrier assembly member 146. The planet carrierassembly member 146 includes a plurality of pinion gears 147 rotatablymounted on a carrier member 149 and disposed in meshing relationshipwith both the sun gear member 142 and the ring gear member 144.

The planetary gear arrangement 118 also includes six torque-transmittingmechanisms 150, 152, 154, 156, 158 and 159. The torque-transmittingmechanisms 150, 152 and 154 are rotating-type torque-transmittingmechanisms, commonly termed clutches. The torque-transmitting mechanisms156, 158 and 159 are stationary-type torque-transmitting mechanisms,commonly termed brakes or reaction clutches.

The input shaft 17 is continuously connected with the sun gear member132. The output shaft 19 is continuously connected with the ring gearmember 144. The sun gear member 122 is continuously connected with thetransmission housing 160. The planet carrier assembly member 126 iscontinuously connected with the ring gear member 134 and the sun gearmember 142 through the interconnecting member 170.

The ring gear member 124 is selectively connectable with the planetcarrier assembly member 136 through the clutch 150. The sun gear member132 is selectively connectable with the planet carrier assembly member146 through the clutch 152. The planet carrier assembly member 136 isselectively connectable with the planet carrier assembly member 146through the clutch 154. The ring gear member 124 is selectivelyconnectable with the transmission housing 160 through the brake 156. Theplanet carrier assembly member 136 is selectively connectable with thetransmission housing 160 through the brake 158. The planet carrierassembly member 146 is selectively connectable with the transmissionhousing 160 through the brake 159.

The truth table of FIG. 2b describes the engagement sequence utilized toprovide seven forward speed ratios and a reverse speed ratio in theplanetary gear arrangement 118 shown in FIG. 2a.

The reverse speed ratio is established with the engagement of the clutch150 and the brake 159. The clutch 150 connects the ring gear member 124to the planet carrier assembly member 136. The brake 159 connects theplanet carrier assembly member 146 to the transmission housing 160. Thering gear member 124 rotates at the same speed as the planet carrierassembly member 136. The planet carrier assembly member 126 rotates atthe same speed as the ring gear member 134 and the sun gear member 142.The sun gear member 122 does not rotate. The planet carrier assemblymember 126 rotates at a speed determined from the speed of the ring gearmember 124 and the ring gear/sun gear tooth ratio of the planetary gearset 120. The sun gear member 132 rotates at the same speed as the inputshaft 17. The planet carrier assembly member 136 rotates at a speeddetermined from the speed of the ring gear member 134, the speed of thesun gear member 132, and the ring gear/sun gear tooth ratio of theplanetary gear set 130. The planet carrier assembly member 146 does notrotate. The ring gear member 144 rotates at the same speed as the outputshaft 19. The ring gear member 144, and therefore the output shaft 19,rotates at a speed determined from the speed of the sun gear member 142and the ring gear/sun gear tooth ratio of the planetary gear set 140.The numerical value of the reverse speed ratio is determined utilizingthe ring gear/sun gear tooth ratios of the planetary gear sets 120, 130and 140.

The first forward speed ratio is established with the engagement of theclutch 154 and the brake 159. The clutch 154 connects the planet carrierassembly member 136 to the planet carrier assembly member 146. The brake159 connects the planet carrier assembly member 146 to the transmissionhousing 160. The planet carrier assembly member 126 rotates at the samespeed as the ring gear member 134 and the sun gear member 142. The sungear member 122 does not rotate. The sun gear member 132 rotates at thesame speed as the input shaft 17. The planet carrier assembly members136 and 146 do not rotate. The ring gear member 134 rotates at a speeddetermined from the speed of the sun gear member 132 and the ringgear/sun gear tooth ratio of the planetary gear set 130. The ring gearmember 144 rotates at the same speed as the output shaft 19. The ringgear member 144, and therefore the output shaft 19, rotates at a speeddetermined from the speed of the sun gear member 142 and the ringgear/sun gear tooth ratio of the planetary gear set 140. The numericalvalue of the first forward speed ratio is determined utilizing the ringgear/sun gear tooth ratios of the planetary gear sets 130 and 140.

The second forward speed ratio is established with the engagement of theclutch 154 and the brake 156. The clutch 154 connects the planet carrierassembly member 136 to the planet carrier assembly member 146. The brake156 connects the ring gear member 124 to the transmission housing 160.The planetary gear set 120, ring gear member 134, and sun gear member142 do not rotate. The planet carrier assembly member 136 rotates at thesame speed as the planet carrier assembly member 146. The sun gearmember 132 rotates at the same speed as the input shaft 17. The planetcarrier assembly member 136 rotates at a speed determined from the speedof the sun gear member 132 and the ring gear/sun gear tooth ratio of theplanetary gear set 130. The ring gear member 144 rotates at the samespeed as the output shaft 19. The ring gear member 144, and thereforethe output shaft 19, rotates at a speed determined from the speed of theplanet carrier assembly member 146 and the ring gear/sun gear toothratio of the planetary gear set 140. The numerical value of the secondforward speed ratio is determined utilizing the ring gear/sun gear toothratios of the planetary gear sets 130 and 140.

The third forward speed ratio is established with the engagement of theclutches 150 and 154. The clutch 150 connects the ring gear member 124to the planet carrier assembly member 136. The clutch 154 connects theplanet carrier assembly member 136 to the planet carrier assembly member146. The ring gear member 124 rotates at the same speed as the planetcarrier assembly members 136 and 146. The planet carrier assembly member126 rotates at the same speed as the ring gear member 134 and the sungear member 142. The sun gear member 122 does not rotate. The planetcarrier assembly member 126 rotates at a speed determined from the speedof the ring gear member 124 and the ring gear/sun gear tooth ratio ofthe planetary gear set 120. The sun gear member 132 rotates at the samespeed as the input shaft 17. The planet carrier assembly member 136rotates at a speed determined from the speed of the ring gear member134, the speed, of the sun gear member 132, and the ring gear/sun geartooth ratio of the planetary gear set 130. The ring gear member 144rotates at the same speed as the output shaft 19. The ring gear member144, and therefore the output shaft 19, rotates at a speed determinedfrom the speed of the planet carrier assembly member 146, the speed ofthe sun gear member 142 and the ring gear/sun gear tooth ratio of theplanetary gear set 140. The numerical value of the third forward speedratio is determined utilizing the ring gear/sun gear tooth ratios of theplanetary gear sets 120, 130 and 140.

The fourth forward speed ratio is established with the engagement of theclutches 152 and 154. In this configuration, the input shaft 17 isdirectly connected to the output shaft 19. The numerical value of thefourth forward speed ratio is 1.

The fifth forward speed ratio is established with the engagement of theclutches 150 and 152. The clutch 150 connects the ring gear member 124to the planet carrier assembly member 136. The clutch 152 connects thesun gear member 132 to the planet carrier assembly member 146. The ringgear member 124 rotates at the same speed as the planet carrier assemblymember 136. The planet carrier assembly member 126 rotates at the samespeed as the ring gear member 134 and the sun gear member 142. The sungear member 122 does not rotate. The planet carrier assembly member 126rotates at a speed determined from the speed of the ring gear member 124and the ring gear/sun gear tooth ratio of the planetary gear set 120.The sun gear member 132 and planet carrier assembly member 146 rotate atthe same speed as the input shaft 17. The planet carrier assembly member136 rotates at a speed determined from the speed of the ring gear member134, the speed of the sun gear member 132, and the ring gear/sun geartooth ratio of the planetary gear set 130. The ring gear member 144rotates at the same speed as the output shaft 19. The ring gear member144, and therefore the output shaft 19, rotates at a speed determinedfrom the speed of the planet carrier assembly member 146, the speed ofthe sun gear member 142 and the ring gear/sun gear tooth ratio of theplanetary gear set 140. The numerical value of the fifth forward speedratio is determined utilizing the ring gear/sun gear tooth ratios of theplanetary gear sets 120, 130 and 140.

The sixth forward speed ratio is established with the engagement of theclutch 152 and the brake 156. The clutch 152 connects the sun gearmember 132 to the planet carrier assembly member 146. The brake 156connects the ring gear member 124 to the transmission housing 160. Theplanetary gear set 120, ring gear member 134, and sun gear member 142 donot rotate. The sun gear member 132 and planet carrier assembly member146 rotate at the same speed as the input shaft 17. The ring gear member144 rotates at the same speed as the output shaft 19. The ring gearmember 144, and therefore the output shaft 19, rotates at a speeddetermined from the speed of the planet carrier assembly member 146 andthe ring gear/sun gear tooth ratio of the planetary gear set 140. Thenumerical value of the sixth forward speed ratio is determined utilizingthe ring gear/sun gear tooth ratio of the planetary gear set 140.

The seventh forward speed ratio is established with the engagement ofthe clutch 152 and the brake 158. The clutch 152 connects the sun gearmember 132 to the planet carrier assembly member 146. The brake 158connects the planet carrier assembly member 136 to the transmissionhousing 160. The planet carrier assembly member 126 rotates at the samespeed as the ring gear member 134 and the sun gear member 142. The sungear member 122 and planet carrier assembly member 136 do not rotate.The sun gear member 132 and planet carrier assembly member 146 rotate atthe same speed as the input shaft 17. The ring gear member 134 rotatesat a speed determined from the speed of the sun gear member 132 and thering gear/sun gear tooth ratio of the planetary gear set 130. The ringgear member 144 rotates at the same speed as the output shaft 19. Thering gear member 144, and therefore the output shaft 19, rotates at aspeed determined from the speed of the planet carrier assembly member146, the speed of the sun gear member 142, and the ring gear/sun geartooth ratio of the planetary gear set 140. The numerical value of theseventh forward speed ratio is determined utilizing the ring gear/sungear tooth ratios of the planetary gear sets 130 and 140.

As set forth above, the truth table of FIG. 2b describes the engagementsequence of the torque-transmitting mechanisms utilized to provide areverse drive ratio and seven forward speed ratios. The truth table alsoprovides an example of the ratios that can be attained with the familymembers shown in FIG. 2a utilizing the sample tooth ratios given in FIG.2b. The R1/S1 value is the tooth ratio of the planetary gear set 120;the R2/S2 value is the tooth ratio of the planetary gear set 130; andthe R3/S3 value is the tooth ratio of the planetary gear set 140. Alsoshown in FIG. 2b are the ratio steps between single step ratios in theforward direction as well as the reverse to first ratio step ratio. Forexample, the first to second step ratio is 1.96.

Turning to FIG. 3a, a powertrain 210 includes the engine and torqueconverter 12, a planetary transmission 214, and a final drive mechanism16. The planetary transmission 214 includes an input shaft 17continuously connected with the engine and torque converter 12, aplanetary gear arrangement 218, and an output shaft 19 continuouslyconnected with the final drive mechanism 16. The planetary geararrangement 218 includes three planetary gear sets 220, 230 and 240.

The planetary gear set 220 includes a sun gear member 222, a ring gearmember 224, and a planet carrier assembly 226. The planet carrierassembly 226 includes a plurality of pinion gears 227 rotatably mountedon a carrier member 229 and disposed in meshing relationship with boththe sun gear member 222 and the ring gear member 224.

The planetary gear set 230 includes a sun gear member 232, a ring gearmember 234, and a planet carrier assembly member 236. The planet carrierassembly member 236 includes a plurality of pinion gears 237 rotatablymounted on a carrier member 239 and disposed in meshing relationshipwith both the sun gear member 232 and the ring gear member 234.

The planetary gear set 240 includes a sun gear member 242, a ring gearmember 244, and a planet carrier assembly member 246. The planet carrierassembly member 246 includes a plurality of pinion gears 247 rotatablymounted on a carrier member 249 and disposed in meshing relationshipwith both the sun gear member 242 and the ring gear member 244.

The planetary gear arrangement 218 also includes six torque-transmittingmechanisms 250, 252, 254, 256, 258 and 259. The torque-transmittingmechanisms 250, 252, 254 and 256 are rotating type torque-transmittingmechanisms, commonly termed clutches. The torque-transmitting mechanisms258 and 259 are stationary type torque-transmitting mechanisms, commonlytermed brakes or reaction clutches.

The input shaft 17 is continuously connected with the sun gear member242, and the output shaft 19 is continuously connected with the ringgear member 234. The sun gear member 222 is continuously connected withthe transmission housing 260. The ring gear member 224 is continuouslyconnected with the sun gear member 232 and the planet carrier assemblymember 246 through the interconnecting member 270.

The planet carrier assembly member 226 is selectively connectable withthe planet carrier assembly member 236 through the clutch 250. Theplanet carrier assembly member 226 is selectively connectable with thering gear member 244 through the clutch 152. The planet carrier assemblymember 246 is selectively connectable with the sun gear member 242through the clutch 254. The planet carrier assembly member 236 isselectively connectable with the sun gear member 242 through the clutch256. The planet carrier assembly member 236 is selectively connectablewith the transmission housing 260 through the brake 258. The ring gearmember 244 is selectively connectable with the transmission housing 260through the brake 259.

As shown in the truth table in FIG. 3b, the torque-transmittingmechanisms are engaged in combinations of two to establish seven forwardspeed ratios and one reverse ratio.

The reverse speed ratio is established with the engagement of the clutch254 and the brake 258. The clutch 254 connects the planet carrierassembly member 246 to the sun gear member 242. The brake 258 connectsthe planet carrier assembly member 236 to the transmission housing 260.The sun gear member 222 does not rotate. The ring gear member 224, sungear member 232, planet carrier assembly member 246, and sun gear member242 rotate at the same speed as the input shaft 17. The planet carrierassembly member 236 does not rotate. The ring gear member 234 rotates atthe same speed as the output shaft 19. The ring gear member 234, andtherefore the output shaft 19, rotates at a speed determined from thespeed of the sun gear member 232 and the ring gear/sun gear tooth ratioof the planetary gear set 230. The numerical value of the reverse speedratio is determined utilizing the ring gear/sun gear tooth ratio of theplanetary gear set 230.

The first forward speed ratio is established with the engagement of theclutch 250 and the brake 259. The clutch 250 connects the planet carrierassembly member 226 to the planet carrier assembly member 236. The brake259 connects the ring gear member 244 to the transmission housing 260.The sun gear member 222 does not rotate. The planet carrier assemblymember 226 rotates at the same speed as the planet carrier assemblymember 236. The ring gear member 224 rotates at the same speed as thesun gear member 232 and the planet carrier assembly member 246. Theplanet carrier assembly member 226 rotates at a speed determined fromthe speed of the ring gear member 224 and the ring gear/sun gear toothratio of the planetary gear set 220. The ring gear member 234 rotates atthe same speed as the output shaft 19. The ring gear member 234, andtherefore the output shaft 19, rotates at a speed determined from thespeed of the planet carrier assembly member 236, the speed of the sungear member 232, and the ring gear/sun gear tooth ratio of the planetarygear set 230. The sun gear member 242 rotates at the same speed as theinput shaft 17. The ring gear member 244 does not rotate. The planetcarrier assembly member 246 rotates at a speed determined from the speedof the sun gear member 242 and the ring gear/sun gear tooth ratio of theplanetary gear set 240. The numerical value of the first forward speedratio is determined utilizing the ring gear/sun gear tooth ratios of theplanetary gear sets 220, 230 and 240.

The second forward speed ratio is established with the engagement of theclutches 250 and 252. The clutch 250 connects the planet carrierassembly member 226 to the planet carrier assembly member 236. Theclutch 252 connects the planet carrier assembly member 226 to the ringgear member 244. The ring gear member 224 rotates at the same speed asthe sun gear member 232 and the planet carrier assembly member 246. Theplanet carrier assembly member 226 rotates at the same speed as theplanet carrier assembly member 236 and the ring gear member 244. The sungear member 222 does not rotate. The planet carrier assembly member 226rotates at a speed determined from the speed of the ring gear member 224and the ring gear/sun gear tooth ratio of the planetary gear set 220.The ring gear member 234 rotates at the same speed as the output shaft19. The ring gear member 234, and therefore the output shaft 19, rotatesat a speed determined from the speed of the planet carrier assemblymember 236, the speed of the sun gear member 232, and the ring gear/sungear tooth ratio of the planetary gear set 230. The sun gear member 242rotates at the same speed as the input shaft 17. The planet carrierassembly member 246 rotates at a speed determined from the speed of thering gear member 244, the speed of the sun gear member 242, and the ringgear/sun gear tooth ratio of the planetary gear set 240. The numericalvalue of the second forward speed ratio is determined utilizing the ringgear/sun gear tooth ratios of the planetary gear sets 220, 230 and 240.

The third forward speed ratio is established with the engagement of theclutches 250 and 254. The clutch 250 connects the planet carrierassembly member 226 to the planet carrier assembly member 236. Theclutch 254 connects the planet carrier assembly member 246 to the sungear member 242. The sun gear member 222 does not rotate. The planetcarrier assembly member 226 rotates at the same speed as the planetcarrier assembly member 236. The ring gear member 224, sun gear member232, planet carrier assembly member 246, and sun gear member 242 rotateat the same speed as the input shaft 17. The planet carrier assemblymember 226 rotates at a speed determined from the speed of the ring gearmember 224 and the ring gear/sun gear tooth ratio of the planetary gearset 220. The ring gear member 234 rotates at the same speed as theoutput shaft 19. The ring gear member 234, and therefore the outputshaft 19, rotates at a speed determined from the speed of the planetcarrier assembly member 236, the speed of the sun gear member 232, andthe ring gear/sun gear tooth ratio of the planetary gear set 230. Thenumerical value of the third forward speed ratio is determined utilizingthe ring gear/sun gear tooth ratios of the planetary gear sets 220 and230.

The fourth forward speed ratio is established with the engagement of theclutches 250 and 256. The clutch 250 connects the planet carrierassembly member 226 to the planet carrier assembly member 236. Theclutch 256 connects the planet carrier assembly member 236 to the sungear member 242. The sun gear member 222 does not rotate. The planetcarrier assembly member 226, planet carrier assembly member 236, and sungear member 242 rotate at the same speed as the input shaft 17. The ringgear member 224 rotates at the same speed as the sun gear member 232 andthe planet carrier assembly member 246. The planet carrier assemblymember 226 rotates at a speed determined from the speed of the ring gearmember 224 and the ring gear/sun gear tooth ratio of the planetary gearset 220. The ring gear member. 234 rotates at the same speed as theoutput shaft 19. The ring gear member 234, and therefore the outputshaft 19, rotates at a speed determined from the speed of the planetcarrier assembly member 236, the speed of the sun gear member 232, andthe ring gear/sun gear tooth ratio of the planetary gear set 230. Thenumerical value of the fourth forward speed ratio is determinedutilizing the ring gear/sun gear tooth ratios of the planetary gear sets220 and 230.

The fifth forward speed ratio is established with the engagement of theclutches 254 and 256. In this configuration, the input shaft 17 isdirectly connected to the output shaft 19. The numerical value of thefifth forward speed ratio is 1.

The sixth forward speed ratio is established with the engagement of theclutches 252 and 256. The clutch 252 connects the planet carrierassembly member 226 to the ring gear member 244. The clutch 256 connectsthe planet carrier assembly member 236 to the sun gear member 242. Thesun gear member 222 does not rotate. The planet carrier assembly member226 rotates at the same speed as the ring gear member 244. The ring gearmember 224 rotates at the same speed as the sun gear member 232 and theplanet carrier assembly member 246. The planet carrier assembly member226 rotates at a speed determined from the speed of the ring gear member224 and the ring gear/sun gear tooth ratio of the planetary gear set220. The ring gear member 234 rotates at the same speed as the outputshaft 19. The planet carrier assembly member 236 and sun gear member 242rotate at the same speed as the input shaft 17. The ring gear member234, and therefore the output shaft 19, rotates at a speed determinedfrom the speed of the planet carrier assembly member 236, the speed ofthe sun gear member 242, and the ring gear/sun gear tooth ratio of theplanetary gear set 230. The planet carrier assembly member 246 rotatesat a speed determined from the speed of the ring gear member 244, thespeed of the sun gear member 242, and the ring gear/sun gear tooth ratioof the planetary gear set 240. The numerical value of the sixth forwardspeed ratio is determined utilizing the ring gear/sun gear tooth ratiosof the planetary gear sets 220, 230 and 240.

The seventh forward speed ratio is established with the engagement ofthe clutch 256 and the brake 259. The clutch 256 connects the planetcarrier assembly member 236 to the sun gear member 242. The brake 259connects the ring gear member 244 to the transmission housing 260. Thesun gear member 222 does not rotate. The ring gear member 224 rotates atthe same speed as the sun gear member 232 and the planet carrierassembly member 246. The planet carrier assembly member 236 and sun gearmember 242 rotate at the same speed as the input shaft 17. The ring gearmember 234 rotates at the same speed as the output shaft 19. The ringgear member 234, and therefore the output shaft 19, rotates at a speeddetermined from the speed of the planet carrier assembly member 236, thespeed of the sun gear member 232, and the ring gear/sun gear tooth ratioof the planetary gear set 230. The ring gear member 244 does not rotate.The planet carrier assembly member 246 rotates at a speed determinedfrom the speed of the sun gear member 242 and the ring gear/sun geartooth ratio of the planetary gear set 240. The numerical value of theseventh forward speed ratio is determined utilizing the ring gear/sungear tooth ratios of the planetary gear sets 230 and 240.

As previously set forth, the truth table of FIG. 3b describes thecombinations of engagements utilized for the seven forward speed ratiosand reverse ratio. The truth table also provides an example of speedratios that are available with the family member described above. Theseexamples of speed ratios are determined utilizing the tooth ratios givenin FIG. 3b. The R1/S1 value is the tooth ratio of the planetary gear set220; the R2/S2 value is the tooth ratio of the planetary gear set 230;and the R3/S3 value is the tooth ratio of the planetary gear set 240.Also depicted in FIG. 3b is a chart representing the ratio steps betweenadjacent forward speed ratios and the reverse speed ratio. For example,the first to second ratio interchange has a step of 1.66. It can also bereadily determined from the truth table of FIG. 3b that all of thesingle step forward ratio interchanges are of the single transitionvariety, except the reverse to first step. The double step forward ratiointerchanges are also of the single transition variety.

A powertrain 310, shown in FIG. 4a, includes the engine and torqueconverter 12, a planetary transmission 314, and the final drivemechanism 16. The planetary transmission 314 includes an input shaft 17continuously connected with the engine and torque converter 12, aplanetary gear arrangement 318, and output shaft 19 continuouslyconnected with the final drive mechanism 16. The planetary geararrangement 318 includes three planetary gear sets 320, 330 and 340.

The planetary gear set 320 includes a sun gear member 322, a ring gearmember 324, and a planet carrier assembly member 326. The planet carrierassembly member 326 includes a plurality of pinion gears 327 rotatablymounted on a carrier member 329 and disposed in meshing relationshipwith both the sun gear member 322 and the ring gear member 324.

The planetary gear set 330 includes a sun gear member 332, a ring gearmember 334, and a planet carrier assembly member 336. The planet carrierassembly member 336 includes a plurality of pinion gears 337 rotatablymounted on a carrier member 339 and disposed in meshing relationshipwith both the sun gear member 332 and the ring gear member 334.

The planetary gear set 340 includes a sun gear member 342, a ring gearmember 344, and a planet carrier assembly member 346. The planet carrierassembly member 346 includes a plurality of pinion gears 347 rotatablymounted on a carrier member 349 and disposed in meshing relationshipwith both the sun gear member 342 and the ring gear member 344.

The planetary gear arrangement 318 also includes six torque-transmittingmechanisms 350, 352, 354, 356, 358 and 359. The torque-transmittingmechanisms 350, 352, 354 and 356 are rotating type torque-transmittingmechanisms, commonly termed clutches. The torque-transmitting mechanisms358 and 359 are stationary-type torque-transmitting mechanisms, commonlytermed brakes or reaction clutches.

The input shaft 17 is continuously connected with the sun gear member332, and the output shaft 19 is continuously connected with the ringgear member 344. The sun gear member 322 is continuously connected withthe transmission housing 360. The planet carrier assembly member 326 iscontinuously connected with the ring gear member 334 and the sun gearmember 342 through the interconnecting member 370.

The ring gear member 324 is selectively connectable with the sun gearmember 332 through the clutch 350. The ring gear member 324 isselectively connectable with the planet carrier assembly member 336through the clutch 352. The sun gear member 332 is selectivelyconnectable with the planet carrier assembly member 346 through theclutch 354. The planet carrier assembly member 336 is selectivelyconnectable with the planet carrier assembly member 346 through theclutch 356. The ring gear member 324 is selectively connectable with thetransmission housing 360 through the brake 358. The planet carrierassembly member 346 is selectively connectable with the transmissionhousing 360 through the brake 359.

The truth tables given in FIGS. 4b, 5 b, 6 b, 7 b, 8 b, 9 b, 10 b, 11 b,12 b, 13 b, 14 b, 15 b, 16 b, 17 b and 18 b show the engagementsequences for the torque-transmitting mechanisms to provide at leastseven forward speed ratios and at least one reverse ratio. As shown anddescribed above for the configuration in FIGS. 1a, 2 a and 3 a, thoseskilled in the art will understand from the respective truth tables howthe speed ratios are established through the planetary gear setsidentified in the written description.

The truth table shown in FIG. 4b describes the engagement combinationand the engagement sequence necessary to provide the reverse drive ratioand seven forward speed ratios. A sample of the numerical values for theratios is also provided in the truth table of FIG. 4b. These values aredetermined utilizing the ring gear/sun gear tooth ratios also given inFIG. 4b. The R1/S1 value is the tooth ratio for the planetary gear set320; the R2/S2 value is the tooth ratio for the planetary gear set 330;and the R3/S3 value is the tooth ratio for the planetary gear set 340.Also given in FIG. 4b is a chart describing the step ratios between theadjacent forward speed ratios and the reverse to first forward speedratio. For example, the first to second forward speed ratio step is 2.1.It can be readily determined from the truth table of FIG. 4b that eachof the forward single step ratio interchanges is a single transitionshift, as are the double step interchanges.

Those skilled in the art will recognize that the numerical values of thereverse and sixth forward speed ratios are determined utilizing the ringgear/sun gear tooth ratios of the planetary gear sets 320 and 340. Thenumerical values of the first and second forward speed ratios aredetermined utilizing the ring gear/sun gear tooth ratios of theplanetary gear sets 330 and 340. The numerical values of the third,fourth and seventh forward speed ratios are determined utilizing thering gear/sun gear tooth ratios of the planetary gear sets 320, 330 and340. The numerical value of the fifth forward speed ratio is 1.

A powertrain 410, shown in FIG. 5a, includes the engine and torqueconverter 12, a planetary transmission 414 and the final drive mechanism16. The planetary transmission 414 includes a planetary gear arrangement418, input shaft 17 and output shaft 19. The planetary gear arrangement418 includes three simple planetary gear sets 420, 430 and 440.

The planetary gear set 420 includes a sun gear member 422, a ring gearmember 424, and a planet carrier assembly 426. The planet carrierassembly 426 includes a plurality of pinion gears 427 rotatably mountedon a carrier member 429 and disposed in meshing relationship with boththe sun gear member 422 and the ring gear member 424.

The planetary gear set 430 includes a sun gear member 432, a ring gearmember 434, and a planet carrier assembly member 436. The planet carrierassembly member 436 includes a plurality of pinion gears 437 rotatablymounted on a carrier member 439 and disposed in meshing relationshipwith both the sun gear member 432 and the ring gear member 434.

The planetary gear set 440 includes a sun gear member 442, a ring gearmember 444, and a planet carrier assembly member 446. The planet carrierassembly member 446 includes a plurality of pinion gears 447 rotatablymounted on a carrier member 449 and disposed in meshing relationshipwith both the sun gear member 442 and the ring gear member 444.

The planetary gear arrangement 418 also includes six torque-transmittingmechanisms 450, 452, 454, 456, 458 and 459. The torque-transmittingmechanisms 450, 452, 454 and 456 are rotating type torque-transmittingmechanisms, commonly termed clutches. The torque-transmitting mechanisms458 and 459 are stationary-type torque-transmitting mechanisms, commonlytermed brakes or reaction clutches.

The input shaft 17 is continuously connected with the sun gear member442, and the output shaft 19 is continuously connected with the ringgear member 434. The sun gear member 422 is continuously connected withthe transmission housing 460. The planet carrier assembly member 426 iscontinuously connected with the sun gear member 432 and the ring gearmember 444 through the interconnecting member 470.

The ring gear member 424 is selectively connectable with the planetcarrier assembly member 426 through the clutch 450. The ring gear member424 is selectively connectable with the planet carrier assembly member446 through the clutch 452. The planet carrier assembly member 436 isselectively connectable with the planet carrier assembly member 446through the clutch 454. The planet carrier assembly member 436 isselectively connectable with the sun gear member 442 through the clutch456. The planet carrier assembly member 436 is selectively connectablewith the transmission housing 460 through the brake 458. The planetcarrier assembly member 446 is selectively connectable with thetransmission housing 460 through the brake 459.

The truth table shown in FIG. 5b describes the engagement combinationand sequence of the torque-transmitting mechanisms 450, 452, 454, 456,458 and 459 that are employed to provide the reverse drive ratio and theseven forward speed ratios. It should be noted that thetorque-transmitting mechanism 458 is engaged through the neutralcondition to simplify the forward/reverse interchange.

Also given in the truth table of FIG. 5b is a set of numerical valuesthat are attainable with the present invention utilizing the ringgear/sun gear tooth ratios shown. The R1/S1 value is the tooth ratio ofthe planetary gear set 420; the R2/S2 value is the tooth ratio of theplanetary gear set 430; and the R3/S3 value is the tooth ratio of theplanetary gear set 440. As can also be determined from the truth tableof FIG. 5b, the single and double step forward interchanges are singletransition shifts.

FIG. 5b also provides a chart of the ratio steps between adjacentforward ratios and between the reverse and first forward ratio. Forexample, the ratio step between the first and second forward ratios is1.81. Those skilled in the art will recognize that the numerical valuesof the reverse, third and fifth forward speed ratios are determinedutilizing the ring gear/sun gear tooth ratios of the planetary gear sets420, 430 and 440. The numerical values of the first, second and seventhforward speed ratios are determined utilizing the ring gear/sun geartooth ratios of the planetary gear sets 430 and 440. The numerical valueof the fourth forward speed ratio is 1. The numerical value of the sixthforward speed ratio is determined utilizing the ring gear/sun gear toothratio of the planetary gear set 430.

A powertrain 510, shown in FIG. 6a, includes an engine and torqueconverter 12, a planetary gear transmission 514 and the final drivemechanism 16. The planetary transmission 514 includes the input shaft17, a planetary gear arrangement 518 and the output shaft 19. Theplanetary gear arrangement 518 includes three planetary gear sets 520,530 and 540.

The planetary gear set 520 includes a sun gear member 522, a ring gearmember 524, and a planet carrier assembly 526. The planet carrierassembly 526 includes a plurality of pinion gears 527 rotatably mountedon a carrier member 529 and disposed in meshing relationship with boththe sun gear member 522 and the ring gear member 524.

The planetary gear set 530 includes a sun gear member 532, a ring gearmember 534, and a planet carrier assembly member 536. The planet carrierassembly member 536 includes a plurality of pinion gears 537 rotatablymounted on a carrier member 539 and disposed in meshing relationshipwith both the sun gear member 532 and the ring gear member 534.

The planetary gear set 540 includes a sun gear member 542, a ring gearmember 544, and a planet carrier assembly member 546. The planet carrierassembly member 546 includes a plurality of pinion gears 547 rotatablymounted on a carrier member 549 and disposed in meshing relationshipwith both the sun gear member 542 and the ring gear member 544.

The planetary gear arrangement 518 also includes six torque-transmittingmechanisms 550, 552, 554, 556, 558 and 559. The torque-transmittingmechanisms 550, 552, 554 and 556 are rotating type torque-transmittingmechanisms, commonly termed clutches. The torque-transmitting mechanisms558 and 559 are stationary-type torque-transmitting mechanisms, commonlytermed brakes or reaction clutches.

The input shaft 17 is continuously connected with the sun gear member542, and the output shaft 19 is continuously connected with the ringgear member 534. The planet carrier assembly member 526 is continuouslyconnected with the transmission housing 560. The sun gear member 522 iscontinuously connected with the sun gear member 532 and with the ringgear member 544 through the interconnecting member 570.

The ring gear member 524 is selectively connectable with the planetcarrier assembly member 546 through the clutch 550. The planet carrierassembly member 536 is selectively connectable with the sun gear member532 through the clutch 552. The planet carrier assembly member 536 isselectively connectable with the planet carrier assembly member 546through the clutch 554. The planet carrier assembly member 536 isselectively connectable with the sun gear member 542 through the clutch556. The sun gear member 522 is selectively connectable with thetransmission housing 560 through the brake 558. The planet carrierassembly member 546 is selectively connectable with the transmissionhousing 560 through the brake 559.

The truth table shown in FIG. 6b describes the engagement sequence andcombination of the torque-transmitting mechanisms to provide two reversespeed ratios and seven forward speed ratios. It should be noted that thetorque-transmitting mechanism 559 can remain engaged through the neutralcondition, thereby simplifying the forward/reverse interchange. It canalso be determined from the truth table of FIG. 6b that all of thesingle and double step forward ratio interchanges are of the singletransition variety. The chart of FIG. 6b describes the ratio stepsbetween adjacent forward speed ratios and the ratio step between thereverse and first forward speed ratio.

Those skilled in the art, upon reviewing the truth table and theschematic representation of FIG. 6a, can determine that the numericalvalue of the reverse speed ratio is determined utilizing the ringgear/sun gear tooth ratio of the planetary gear set 540. The numericalvalues of the first, third and seventh forward speed ratios aredetermined utilizing the ring gear/sun gear tooth ratios of theplanetary gear sets 530 and 540. The numerical values of the second andsixth forward speed ratios are determined utilizing the ring gear/sungear tooth ratios of the planetary gear sets 520, 530 and 540. Thenumerical value of the fourth forward speed ratio is 1. The numericalvalue of the fifth forward speed ratio is determined utilizing the ringgear/sun gear tooth ratio of the planetary gear set 530.

The sample speed ratios given in the truth table are determinedutilizing the tooth ratio values also given in FIG. 6b. The R1/S1 valueis the tooth ratio of the planetary gear set 520; the R2/S2 value is thetooth ratio of the planetary gear set 530; and the R3/S3 value is thetooth ratio of the planetary gear set 540.

A powertrain 610, shown in FIG. 7a, has the engine and torque converter12, a planetary transmission 614 and the final drive mechanism 16. Theplanetary transmission 614 includes the input shaft 17, a planetary geararrangement 618 and the output shaft 19. The planetary gear arrangement618 includes three planetary gear sets 620, 630 and 640.

The planetary gear set 620 includes a sun gear member 622, a ring gearmember 624, and a planet carrier assembly 626. The planet carrierassembly 626 includes a plurality of pinion gears 627 rotatably mountedon a carrier member 629 and disposed in meshing relationship with boththe sun gear member 622 and the ring gear member 624.

The planetary gear set 630 includes a sun gear member 632, a ring gearmember 634, and a planet carrier assembly member 636. The planet carrierassembly member 636 includes a plurality of pinion gears 637 rotatablymounted on a carrier member 639 and disposed in meshing relationshipwith both the sun gear member 632 and the ring gear member 634.

The planetary gear set 640 includes a sun gear member 642, a ring gearmember 644, and a planet carrier assembly member 646. The planet carrierassembly member 646 includes a plurality of pinion gears 647 rotatablymounted on a carrier member 649 and disposed in meshing relationshipwith both the sun gear member 642 and the ring gear member 644.

The planetary gear arrangement 618 also includes six torque-transmittingmechanisms 650, 652, 654, 656, 658 and 659. The torque-transmittingmechanisms 650, 652, 654, 656 and 658 are rotating typetorque-transmitting mechanisms, commonly termed clutches. Thetorque-transmitting mechanism 659 is a stationary-typetorque-transmitting mechanism, commonly termed a brake or reactionclutch.

The input shaft 17 is continuously connected with the planet carrierassembly member 626, and the output shaft 19 is continuously connectedwith the planet carrier assembly member 646. The ring gear member 624 iscontinuously connected with the transmission housing 660. The planetcarrier assembly member 626 is continuously connected with the sun gearmember 632 and ring gear member 644 through the interconnecting member670.

The sun gear member 622 is selectively connectable with the planetcarrier assembly member 636 through the clutch 650. The ring gear member634 is selectively connectable with the planet carrier assembly member646 through the clutch 652. The ring gear member 634 is selectivelyconnectable with the sun gear member 642 through the clutch 654. Theplanet carrier assembly member 636 is selectively connectable with theplanet carrier assembly member 646 through the clutch 656. The planetcarrier assembly member 636 is selectively connectable with the sun gearmember 642 through the clutch 658. The planet carrier assembly member636 is selectively connectable with the transmission housing 660 throughthe brake 659.

The truth table shown in FIG. 7b describes the combination oftorque-transmitting mechanism engagements that will provide the reversedrive ratio and seven forward speed ratios, as well as the sequence ofthese engagements and interchanges. The torque-transmitting mechanism659 can be engaged through the neutral condition, thereby simplifyingthe forward/reverse interchange. It can be noted from the truth tablethat each of the single step forward interchanges are single transitionratio changes.

The ratio values given are by way of example and are establishedutilizing the ring gear/sun gear tooth ratios given in FIG. 7b. Forexample, the R1/S1 value is the tooth ratio of the planetary gear set620; the R2/S2 value is the tooth ratio of the planetary gear set 630;and the R3/S3 value is the tooth ratio of the planetary gear set 640.The ratio steps between adjacent forward ratios and the reverse to firstratio are also given in FIG. 7b.

Those skilled in the art will, upon reviewing the truth table of FIG.7b, recognize that the numerical value of the reverse speed ratio isdetermined utilizing the ring gear/sun gear tooth ratio of the planetarygear set 630. The numerical value of the first forward speed ratio isdetermined utilizing the ring gear/sun gear tooth ratios of theplanetary gear sets 630 and 640. The numerical value of the secondforward speed ratio is determined utilizing the ring gear/sun gear toothratio of the planetary gear set 640. The numerical value of the thirdforward speed ratio is 1. The numerical value of the fourth forwardspeed ratio is determined utilizing the ring gear/sun gear tooth ratiosof the planetary gear sets 620 and 640. The numerical value of the fifthforward speed ratio is determined utilizing the ring gear/sun gear toothratios of the planetary gear sets 620, 630 and 640. The numerical valueof the sixth forward speed ratio is determined utilizing the ringgear/sun gear tooth ratio of the planetary gear set 620. The numericalvalue of the seventh forward speed ratio is determined utilizing thering gear/sun gear tooth ratios of the planetary gear sets 620 and 630.

A powertrain 710, shown in FIG. 8a, has the conventional engine andtorque converter 12, a planetary transmission 714, and the conventionalfinal drive mechanism 16. The engine and torque converter 12 aredrivingly connected with the planetary transmission 714 through theinput shaft 17. The planetary transmission 714 is drivingly connectedwith the final drive mechanism 16 through the output shaft 19. Theplanetary transmission 714 includes a planetary gear arrangement 718that has a first planetary gear set 720, a second planetary gear set730, and a third planetary gear set 740.

The planetary gear set 720 includes a sun gear member 722, a ring gearmember 724, and a planet carrier assembly 726. The planet carrierassembly 726 includes a plurality of pinion gears 727 rotatably mountedon a carrier member 729 and disposed in meshing relationship with boththe sun gear member 722 and the ring gear member 724.

The planetary gear set 730 includes a sun gear member 732, a ring gearmember 734, and a planet carrier assembly member 736. The planet carrierassembly member 736 includes a plurality of pinion gears 737 rotatablymounted on a carrier member 739 and disposed in meshing relationshipwith both the sun gear member 732 and the ring gear member 734.

The planetary gear set 740 includes a sun gear member 742, a ring gearmember 744, and a planet carrier assembly member 746. The planet carrierassembly member 746 includes a plurality of pinion gears 747 rotatablymounted on a carrier member 749 and disposed in meshing relationshipwith both the sun gear member 742 and the ring gear member 744.

The planetary gear arrangement 718 also includes six torque-transmittingmechanisms 750, 752, 754, 756, 758 and 759. The torque-transmittingmechanisms 750, 752, 754 and 756 are rotating type torque-transmittingmechanisms, commonly termed clutches. The torque-transmitting mechanisms758 and 759 are stationary-type torque-transmitting mechanisms, commonlytermed brakes or reaction clutches.

The input shaft 17 is continuously connected with the sun gear member742, and the output shaft 19 is continuously connected with the ringgear member 734. The planet carrier assembly member 726 is continuouslyconnected with the transmission housing 760. The sun gear member 722 iscontinuously connected with the sun gear member 732 and the ring gearmember 744 through the interconnecting member 770.

The ring gear member 724 is selectively connectable with the planetcarrier assembly member 746 through the clutch 750. The planet carrierassembly member 736 is selectively connectable with the sun gear member732 through the clutch 752. The planet carrier assembly member 736 isselectively connectable with the planet carrier assembly member 746through the clutch 754. The planet carrier assembly member 736 isselectively connectable with the sun gear member 742 through the clutch756. The sun gear member 722 is selectively connectable with thetransmission housing 760 through the brake 758. The planet carrierassembly member 736 is selectively connectable with the transmissionhousing 760 through the brake 759.

The truth table of FIG. 8b defines the torque-transmitting mechanismengagement sequence utilized for each of the forward speed ratios andthe reverse speed ratio. Also given in the truth table is a set ofnumerical values that are attainable with the present inventionutilizing the ring gear/sun gear tooth ratios given in FIG. 8b. TheR1/S1 value is the tooth ratio of the planetary gear set 720; the R2/S2value is the tooth ratio of the planetary gear set 730; and the R3/S3value is the tooth ratio of the planetary gear set 740. As can also bedetermined from the truth table of FIG. 8b, the single step forwardinterchanges are single transition shifts, as are the double stepinterchanges in the forward direction.

FIG. 8b also provides a chart of the ratio steps between adjacentforward ratios and between the reverse and first forward ratio. Forexample, the ratio step between the first and second forward ratios is1.72. Those skilled in the art will recognize that the numerical valueof the reverse speed ratio is determined utilizing the ring gear/sungear tooth ratios of the planetary gear sets 720 and 740. The numericalvalues of the first, third and seventh forward speed ratios aredetermined utilizing the ring gear/sun gear tooth ratios of theplanetary gear sets 720, 730 and 740. The numerical values of the secondand fourth forward speed ratios are determined utilizing the ringgear/sun gear tooth ratios of the planetary gear sets 730 and 740. Thenumerical value of the fifth forward speed ratio is 1. The numericalvalue of the sixth forward speed ratio is determined utilizing the ringgear/sun gear tooth ratio of the planetary gear set 730.

A powertrain 810, shown in FIG. 9a, has the conventional engine andtorque converter 12, a planetary transmission 814, and the final drivemechanism 16. The engine and torque converter 12 are drivingly connectedwith the planetary transmission 814 through the input shaft 17. Theplanetary transmission 814 is drivingly connected with the final drivemechanism 16 through the output shaft 19. The planetary transmission 814includes a planetary gear arrangement 818 that has a first planetarygear set 820, a second planetary gear set 830, and a third planetarygear set 840.

The planetary gear set 820 includes a sun gear member 822, a ring gearmember 824, and a planet carrier assembly 826. The planet carrierassembly 826 includes a plurality of pinion gears 827 rotatably mountedon a carrier member 829 and disposed in meshing relationship with boththe sun gear member 822 and the ring gear member 824.

The planetary gear set 830 includes a sun gear member 832, a ring gearmember 834, and a planet carrier assembly member 836. The planet carrierassembly member 836 includes a plurality of pinion gears 837 rotatablymounted on a carrier member 839 and disposed in meshing relationshipwith both the sun gear member 832 and the ring gear member 834.

The planetary gear set 840 includes a sun gear member 842, a ring gearmember 844, and a planet carrier assembly member 846. The planet carrierassembly member 846 includes a plurality of pinion gears 847 rotatablymounted on a carrier member 849 and disposed in meshing relationshipwith both the sun gear member 842 and the ring gear member 844.

The planetary gear arrangement 818 also includes six torque-transmittingmechanisms 850, 852, 854, 856, 858 and 859. The torque-transmittingmechanisms 850, 852, 854, 856 and 858 are rotating typetorque-transmitting mechanisms, commonly termed clutches. Thetorque-transmitting mechanism 859 is a stationary-typetorque-transmitting mechanism, commonly termed brake or reaction clutch.

The input shaft 17 is continuously connected with the sun gear member832, and the output shaft 19 is continuously connected with the ringgear member 844. The sun gear member 822 is continuously connected withthe transmission housing 860. The planet carrier assembly member 826 iscontinuously connected with the ring gear member 834 and the sun gearmember 842 through the interconnecting member 870.

The ring gear member 824 is selectively connectable with the planetcarrier assembly member 826 through the clutch 850. The ring gear member824 is selectively connectable with the planet carrier assembly member836 through the clutch 852. The ring gear member 824 is selectivelyconnectable with the sun gear member 832 through the clutch 854. Theplanet carrier assembly member 836 is selectively connectable with theplanet carrier assembly member 846 through the clutch 856. The sun gearmember 832 is selectively connectable with the planet carrier assemblymember 846 through the clutch 858. The planet carrier assembly member846 is selectively connectable with the transmission housing 860 throughthe brake 859.

The truth table shown in FIG. 9b defines the torque-transmittingmechanism engagement sequence that provides the reverse speed ratio andeight forward speed ratios shown in the truth table and available withthe planetary gear arrangement 818. The truth table indicates that thetorque-transmitting mechanism 859 can remain engaged through the neutralcondition, thereby simplifying the forward/reverse interchange. A sampleof numerical values for the individual ratios is also given in the truthtable of FIG. 9b. These numerical values have been calculated using thering gear/sun gear tooth ratios also given by way of example in FIG. 9b.The R1/S1 value is the tooth ratio of the planetary gear set 820; theR2/S2 value is the tooth ratio of the planetary gear set 830; and theR3/S3 value is the tooth ratio of the planetary gear set 840. It can bereadily recognized from the truth table that all of the single anddouble step forward interchanges are single transition ratiointerchanges. FIG. 9b also describes the ratio steps between adjacentforward ratios and between the reverse and first forward ratio. Forexample, the ratio step between the first and second forward ratios is2.18.

Those skilled in the art of planetary transmissions will recognize thatthe numerical values of the reverse and sixth forward speed ratios aredetermined utilizing the ring gear/sun gear tooth ratios of theplanetary gear sets 820 and 840. The numerical values of the first andsecond forward speed ratios are determined utilizing the ring gear/sungear tooth ratios of the planetary gear sets 830 and 840. The numericalvalues of the third, fourth and seventh forward speed ratios aredetermined utilizing the ring gear/sun gear tooth ratios of theplanetary gear sets 820, 830 and 840. The numerical value of the fifthforward speed ratio is 1. The numerical value of the eighth forwardspeed ratio is determined utilizing the ring gear/sun gear tooth ratioof the planetary gear set 840.

The powertrain 910, shown in FIG. 10a, includes the conventional engineand torque converter 12, a planetary transmission 914, and theconventional final drive mechanism 16. The engine and torque converter12 are drivingly connected with the planetary transmission 914 throughthe input shaft 17. The planetary transmission 914 is drivinglyconnected with the final drive mechanism 16 through the output shaft 19.The planetary transmission 914 includes a planetary gear arrangement 918that has a first planetary gear set 920, a second planetary gear set930, and a third planetary gear set 940.

The planetary gear set 920 includes a sun gear member 922, a ring gearmember 924, and a planet carrier assembly 926. The planet carrierassembly 926 includes a plurality of pinion gears 927 that are rotatablymounted on a carrier member 929 and disposed in meshing relationshipwith the sun gear member 922 and the ring gear member 924, respectively.

The planetary gear set 930 includes a sun gear member 932, a ring gearmember 934, and a planet carrier assembly member 936. The planet carrierassembly member 936 includes a plurality of pinion gears 937 rotatablymounted on a carrier member 939 and disposed in meshing relationshipwith both the sun gear member 932 and the ring gear member 934.

The planetary gear set 940 includes a sun gear member 942, a ring gearmember 944, and a planet carrier assembly member 946. The planet carrierassembly member 946 includes a plurality of pinion gears 947 rotatablymounted on a carrier member 949 and disposed in meshing relationshipwith both the sun gear member 942 and the ring gear member 944.

The planetary gear arrangement 918 also includes six torque-transmittingmechanisms 950, 952, 954, 956, 958 and 959. The torque-transmittingmechanisms 950, 952, 954, 956 and 958 are rotating typetorque-transmitting mechanisms, commonly termed clutches. Thetorque-transmitting mechanism 959 is a stationary-typetorque-transmitting mechanism, commonly termed brake or reaction clutch.

The input shaft 17 is continuously connected with the sun gear member942, and the output shaft 19 is continuously connected with the ringgear member 934. The planet carrier assembly member 926 is continuouslyconnected with the transmission housing 960. The sun gear member 922 iscontinuously connected with the sun gear member 932 and the ring gearmember 944 through the interconnecting member 970.

The ring gear member 924 is selectively connectable with the sun gearmember 922 through the clutch 950. The ring gear member 924 isselectively connectable with the planet carrier assembly member 946through the clutch 952. The planet carrier assembly member 936 isselectively connectable with the sun gear member 932 through the clutch954. The planet carrier assembly member 936 is selectively connectablewith the planet carrier assembly member 946 through the clutch 956. Theplanet carrier assembly member 936 is selectively connectable with thesun gear member 942 through the clutch 958. The planet carrier assemblymember 936 is selectively connectable with the transmission housing 960through the brake 959.

The truth table of FIG. 10b describes the torque-transmitting mechanismengagement sequence utilized to provide the reverse speed ratio andseven forward speed ratios. The truth table also provides a set ofexamples for the ratios for each of the reverse and forward speedratios. These numerical values have been determined utilizing the ringgear/sun gear tooth ratios given in FIG. 10b. The R1/S1 value is thetooth ratio of the planetary gear set 920; the R2/S2 value is the toothratio of the planetary gear set 930; and the R3/S3 value is the toothratio of the planetary gear set 940. It can also be determined from thetruth table of FIG. 10b that each of the forward single and double stepratio interchanges are of the single transition variety.

Those skilled in the art, upon reviewing the engagement combinations,will recognize that the numerical value of the reverse speed ratio isdetermined utilizing the ring gear/sun gear tooth ratios of theplanetary gear sets 920 and 940. The numerical values of the first,third and seventh forward speed ratios are determined utilizing the ringgear/sun gear tooth ratios of the planetary gear sets 920, 930 and 940.The numerical values of the second and fourth forward speed ratios aredetermined utilizing the ring gear/sun gear tooth ratios of theplanetary gear sets 930 and 940. The numerical value of the fifthforward speed ratio is 1. The numerical value of the sixth forward speedratio is determined utilizing the ring gear/sun gear tooth ratio of theplanetary gear set 930.

A powertrain 1010, shown in FIG. 11a, includes the conventional engineand torque converter 12, a planetary transmission 1014, and theconventional final drive mechanism 16. The engine and torque converterare drivingly connected with the planetary transmission 1014 through theinput shaft 17. The planetary transmission 1014 is drivingly connectedwith the final drive mechanism 16 through the output shaft 19. Theplanetary transmission 1014 includes a planetary gear arrangement 1018that has a first planetary gear set 1020, a second planetary gear set1030, and a third planetary gear set 1040.

The planetary gear set 1020 includes a sun gear member 1022, a ring gearmember 1024, and a planet carrier assembly 1026. The planet carrierassembly 1026 includes a plurality of pinion gears 1027 rotatablymounted on a carrier member 1029 and disposed in meshing relationshipwith both the sun gear member 1022 and the ring gear member 1024.

The planetary gear set 1030 includes a sun gear member 1032, a ring gearmember 1034, and a planet carrier assembly member 1036. The planetcarrier assembly member 1036 includes a plurality of pinion gears 1037rotatably mounted on a carrier member 1039 and disposed in meshingrelationship with both the sun gear member 1032 and the ring gear member1034.

The planetary gear set 1040 includes a sun gear member 1042, a ring gearmember 1044, and a planet carrier assembly member 1046. The planetcarrier assembly member 1046 includes a plurality of pinion gears 1047rotatably mounted on a carrier member 1049 and disposed in meshingrelationship with both the sun gear member 1042 and the ring gear member1044.

The planetary gear arrangement 1018 also includes sixtorque-transmitting mechanisms 1050, 1052, 1054, 1056, 1058 and 1059.The torque-transmitting mechanisms 1050, 1052, 1054, 1056 and 1058 arerotating type torque-transmitting mechanisms, commonly termed clutches.The torque-transmitting mechanism 1059 is a stationary-typetorque-transmitting mechanism, commonly termed brake or reaction clutch.

The input shaft 17 is continuously connected with the ring gear member1044, and the output shaft 19 is continuously connected with the planetcarrier assembly member 1036. The ring gear member 1024 is continuouslyconnected with the transmission housing 1060. The sun gear member 1022is continuously connected with the ring gear member 1034 and the sungear member 1042 through the interconnecting member 1070.

The planet carrier assembly member 1026 is selectively connectable withthe planet carrier assembly member 1036 through the clutch 1050. Theplanet carrier assembly member 1026 is selectively connectable with thering gear member 1044 through the clutch 1052. The planet carrierassembly member 1036 is selectively connectable with the planet carrierassembly member 1046 through the clutch 1054. The sun gear member 1032is selectively connectable with the planet carrier assembly member 1046through the clutch 1056. The ring gear member 1044 is selectivelyconnectable with the sun gear member 1032 through the clutch 1058. Theplanet carrier assembly member 1026 is selectively connectable with thetransmission housing 1060 through the brake 1059.

The truth table shown in FIG. 11b describes the engagement combinationsand the engagement sequence necessary to provide the reverse drive ratioand the eight forward speed ratios. A sample of the numerical values forthe ratios is also provided in the truth table of FIG. 11b. These valuesare determined utilizing the ring gear/sun gear tooth ratios also givenin FIG. 11b. The R1/S1 value is the tooth ratio for the planetary gearset 1020; the R2/S2 value is the tooth ratio for the planetary gear set1030; and the R3/S3 value is the tooth ratio for the planetary gear set1040. Also given in FIG. 11b is a chart describing the step ratiosbetween the adjacent forward speed ratios and the reverse to firstforward speed ratio.

Those skilled in the art will recognize that the numerical values of thereverse and sixth forward speed ratios are determined utilizing the ringgear/sun gear tooth ratios of the planetary gear sets 1020 and 1030. Thenumerical values of the first and fifth forward speed ratios aredetermined utilizing the ring gear/sun gear tooth ratios of theplanetary gear sets 1030 and 1040. The numerical value of the secondforward speed ratio is determined utilizing the ring gear/sun gear toothratio of the planetary gear set 1030. The numerical value of the thirdforward speed ratio is determined utilizing the ring gear/sun gear toothratio of the planetary gear set 1040. The numerical value of the fourthforward speed ratio is 1. The numerical value of the seventh forwardspeed ratio is determined utilizing the ring gear/sun gear tooth ratiosof the planetary gear sets 1020, 1030 and 1040. The numerical value ofthe eighth forward speed ratio is determined utilizing the ring gear/sungear tooth ratios of the planetary gear sets 1020 and 1040.

A powertrain 1110, shown in FIG. 12a, has a conventional engine andtorque converter 12, a planetary transmission 1114, and the conventionalfinal drive mechanism 16. The planetary transmission 1114 includes aplanetary gear arrangement 1118 which is connected with the engine andtorque converter 12 through the input shaft 17 and with the final drivemechanism 16 through the output shaft 19. The planetary gear arrangement1118 includes three planetary gear sets 1120, 1130 and 1140.

The planetary gear set 1120 includes a sun gear member 1122, a ring gearmember 1124, and a planet carrier assembly 1126. The planet carrierassembly 1126 includes a plurality of pinion gears 1127 rotatablymounted on a carrier member 1129 and disposed in meshing relationshipwith both the sun gear member 1122 and the ring gear member 1124.

The planetary gear set 1130 includes a sun gear member 1132, a ring gearmember 1134, and a planet carrier assembly member 1136. The planetcarrier assembly member 1136 includes a plurality of intermeshing piniongears 1137 that are rotatably mounted on a carrier member 1139 anddisposed in meshing relationship with both the sun gear member 1132 andthe ring gear member 1134.

The planetary gear set 1140 includes a sun gear member 1142, a ring gearmember 1144, and a planet carrier assembly member 1146. The planetcarrier assembly member 1146 includes a plurality of pinion gears 1147rotatably mounted on a carrier member 1149 and disposed in meshingrelationship with both the sun gear member 1142 and the ring gear member1144.

The planetary gear arrangement 1118 also includes sixtorque-transmitting mechanisms 1150, 1152, 1154, 1156, 1158 and 1159.The torque-transmitting mechanisms 1150, 1152, 1154, 1156 and 1158 arerotating type torque-transmitting mechanisms, commonly termed clutches.The torque-transmitting mechanism 1159 is a stationary-typetorque-transmitting mechanism, commonly termed brake or reaction clutch.

The input shaft 17 is continuously connected with the sun gear member1142, and the output shaft 19 is continuously connected with the ringgear member 1134. The planet carrier assembly member 1126 iscontinuously connected with the transmission housing 1160. The sun gearmember 1122 is continuously connected with the sun gear member 1132 andthe ring gear member 1144 through the interconnecting member 1170.

The ring gear member 1124 is selectively connectable with the sun gearmember 1122 through the clutch 1150. The ring gear member 1124 isselectively connectable with the planet carrier assembly member 1146through the clutch 1152. The sun gear member 1122 is selectivelyconnectable with the planet carrier assembly member 1136 through theclutch 1154. The planet carrier assembly member 1136 is selectivelyconnectable with the planet carrier assembly member 1146 through theclutch 1156. The planet carrier assembly member 1136 is selectivelyconnectable with the sun gear member 1146 through the clutch 1158. Theplanet carrier assembly member 1146 is selectively connectable with thetransmission housing 1160 through the brake 1159.

The truth table shown in FIG. 12b describes the engagement sequence andengagement combinations utilized with the present family member toprovide the reverse drive ratio and seven forward speed ratios. Thetruth table of FIG. 12b also provides a set of example numbers that canbe established in the planetary gear arrangement 1118 utilizing the ringgear/sun gear tooth ratios. The R1/S1 value is the ring gear/sun geartooth ratio of the planetary gear set 1120; the R2/S2 value is the ringgear/sun gear tooth ratio of the planetary gear set 1130; and the R3/S3value is the ring gear/sun gear tooth ratio of the planetary gear set1140.

The chart of FIG. 12b describes the ratio steps between adjacent forwardspeed ratios for a seven-speed transmission. These step ratios areestablished utilizing the example speed ratios given in the truth table.

Those skilled in the art will recognize that the numerical value of thereverse speed ratio is determined utilizing the ring gear/sun gear toothratio of the planetary gear set 1140. The numerical values of the first,third and seventh forward speed ratios are determined utilizing the ringgear/sun gear tooth ratios of the planetary gear sets 1130 and 1140. Thenumerical values of the second and sixth forward speed ratios aredetermined utilizing the ring gear/sun gear tooth ratios of theplanetary gear sets 1120, 1130 and 1140. The numerical value of thefourth forward speed ratio is 1. The numerical value of the fifthforward speed ratio is determined utilizing the ring gear/sun gear toothratio of the planetary gear set 1130.

A powertrain 1210, shown in FIG. 13a, includes the conventional engineand torque converter 12, a planetary transmission 1214, and theconventional final drive mechanism 16. The engine and torque converterare drivingly connected with the planetary transmission 1214 through theinput shaft 17. The planetary transmission 1214 is drivingly connectedwith the final drive mechanism 16 through the output shaft 19. Theplanetary transmission 1214 includes a planetary gear arrangement 1218that has a first planetary gear set 1220, a second planetary gear set1230, and a third planetary gear set 1240.

The planetary gear set 1220 includes a sun gear member 1222, a ring gearmember 1224, and a planet carrier assembly 1226. The planet carrierassembly 1226 includes a plurality of pinion gears 1227 rotatablymounted on a carrier member 1229 and disposed in meshing relationshipwith both the sun gear member 1222 and the ring gear member 1224.

The planetary gear set 1230 includes a sun gear member 1232, a ring gearmember 1234, and a planet carrier assembly member 1236. The planetcarrier assembly member 1236 includes a plurality of pinion gears 1237rotatably mounted on a carrier member 1239 and disposed in meshingrelationship with both the sun gear member 1232 and the ring gear member1234.

The planetary gear set 1240 includes a sun gear member 1242, a ring gearmember 1244, and a planet carrier assembly member 1246. The planetcarrier assembly member 1246 includes a plurality of pinion gears 1247rotatably mounted on a carrier member 1249 and disposed in meshingrelationship with both the sun gear member 1242 and the ring gear member1244.

The planetary gear arrangement 1218 also includes sixtorque-transmitting mechanisms 1250, 1252, 1254, 1256, 1258 and 1259.The torque-transmitting mechanisms 1250, 1252, 1254, 1256 and 1258 arerotating type torque-transmitting mechanisms, commonly termed clutches.The torque-transmitting mechanism 1259 is a stationary-typetorque-transmitting mechanism, commonly termed brake or reaction clutch.

The input shaft 17 is continuously connected with the ring gear member1234, and the output shaft 19 is continuously connected with the planetcarrier assembly member 1246. The sun gear member 1222 is continuouslyconnected with the transmission housing 1260. The planet carrierassembly member 1226 is continuously connected with the planet carrierassembly member 1236 and the ring gear member 1244 through theinterconnecting member 1270.

The ring gear member 1224 is selectively connectable with the sun gearmember 1232 through the clutch 1250. The ring gear member 1224 isselectively connectable with the planet carrier assembly member 1246through the clutch 1252. The ring gear member 1224 is selectivelyconnectable with the sun gear member 1242 through the clutch 1254. Thesun gear member 1232 is selectively connectable with the sun gear member1242 through the clutch 1256. The ring gear member 1234 is selectivelyconnectable with the sun gear member 1242 through the clutch 1258. Theplanet carrier assembly member 1226 is selectively connectable with thetransmission housing 1260 through the brake 1259.

The truth table shown in FIG. 13b describes the engagement combinationsand the engagement sequence necessary to provide a reverse speed ratioand seven forward speed ratios. A sample of the numerical values for theratios is also provided in the truth table of FIG. 13b. These values aredetermined utilizing the ring gear/sun gear tooth ratios also given inFIG. 13b. The R1/S1 value is the tooth ratio for the planetary gear set1220; the R2/S2 value is the tooth ratio for the planetary gear set1230; and the R3/S3 value is the tooth ratio for the planetary gear set1240. Also given in FIG. 13b is a chart describing the step ratiosbetween the adjacent forward speed ratios and the reverse to firstforward speed ratio.

Those skilled in the art will recognize that the numerical value of thereverse speed ratio is determined utilizing the ring gear/sun gear toothratios of the planetary gear sets 1230 and 1240. The numerical value ofthe first forward speed ratio is determined utilizing the ring gear/sungear tooth ratio of the planetary gear set 1240. The numerical values ofthe second and third forward speed ratios are determined utilizing thering gear/sun gear tooth ratios of the planetary gear sets 1220 and1240. The numerical value of the fourth forward speed ratio is 1. Thenumerical values of the fifth and sixth forward speed ratios aredetermined utilizing the ring gear/sun gear tooth ratios of theplanetary gear sets 1220, 1230 and 1240. The numerical value of theseventh forward speed ratio is determined utilizing the ring gear/sungear tooth ratios of the planetary gear sets 1220 and 1230.

A powertrain 1310, shown in FIG. 14a, includes the conventional engineand torque converter 12, a planetary transmission 1314, and theconventional final drive mechanism 16. The engine and torque converterare drivingly connected with the planetary transmission 1314 through theinput shaft 17. The planetary transmission 1314 is drivingly connectedwith the final drive mechanism 16 through the output shaft 19. Theplanetary transmission 1314 includes a planetary gear arrangement 1318that has a first planetary gear set 1320, a second planetary gear set1330, and a third planetary gear set 1340.

The planetary gear set 1320 includes a sun gear member 1322, a ring gearmember 1324, and a planet carrier assembly 1326. The planet carrierassembly 1326 includes a plurality of pinion gears 1327 rotatablymounted on a carrier member 1329 and disposed in meshing relationshipwith both the sun gear member 1322 and the ring gear member 1324.

The planetary gear set 1330 includes a sun gear member 1332, a ring gearmember 1334, and a planet carrier assembly member 1336. The planetcarrier assembly member 1336 includes a plurality of pinion gears 1337rotatably mounted on a carrier member 1339 and disposed in meshingrelationship with both the sun gear member 1332 and the ring gear member1334.

The planetary gear set 1340 includes a sun gear member 1342, a ring gearmember 1344, and a planet carrier assembly member 1346. The planetcarrier assembly member 1346 includes a plurality of pinion gears 1347rotatably mounted on a carrier member 1349 and disposed in meshingrelationship with both the sun gear member 1342 and the ring gear member1344.

The planetary gear arrangement 1318 also includes sixtorque-transmitting mechanisms 1350, 1352, 1354, 1356, 1358 and 1359.The torque-transmitting mechanisms 1350, 1352, 1354, 1356 and 1358 arerotating type torque-transmitting mechanisms, commonly termed clutches.The torque-transmitting mechanism 1359 is a stationary-typetorque-transmitting mechanism, commonly termed brake or reaction clutch.

The input shaft 17 is continuously connected with the sun gear member1332, and the output shaft 19 is continuously connected with the ringgear member 1344. The sun gear member 1322 is continuously connectedwith the transmission housing 1360. The ring gear member 1324 iscontinuously connected with the ring gear member 1334 and the sun gearmember 1342 through the interconnecting member 1370.

The ring gear member 1324 is selectively connectable with the planetcarrier assembly member 1326 through the clutch 1350. The planet carrierassembly member 1326 is selectively connectable with the planet carrierassembly member 1336 through the clutch 1352. The planet carrierassembly member 1326 is selectively connectable with the ring gearmember 1344 through the clutch 1354. The ring gear member 1344 isselectively connectable with the sun gear member 1342 through the clutch1356. The planet carrier assembly member 1336 is selectively connectablewith the planet carrier assembly member 1346 through the clutch 1358.The planet carrier assembly member 1336 is selectively connectable withthe transmission housing 1360 through the brake 1359.

The truth table shown in FIG. 14b describes the engagement combinationsand the engagement sequence necessary to provide the reverse drive ratioand seven forward speed ratios. A sample of the numerical values for theratios is also provided in the truth table of FIG. 14b. These values aredetermined utilizing the ring gear/sun gear tooth ratios also given inFIG. 14b. The R1/S1 value is the tooth ratio for the planetary gear set1320; the R2/S2 value is the tooth ratio for the planetary gear set1330; and the R3/S3 value is the tooth ratio for the planetary gear set1340. Also given in FIG. 14b is a chart describing the step ratiosbetween the adjacent forward speed ratios and the reverse to firstforward speed ratio.

Those skilled in the art will recognize that the numerical value of thereverse speed ratio is determined utilizing the ring gear/sun gear toothratio of the planetary gear set 1330. The numerical values of the firstand second forward speed ratios are determined utilizing the ringgear/sun gear tooth ratios of the planetary gear sets 1330 and 1340. Thenumerical value of the third forward speed ratio is 1. The numericalvalues of the fourth and fifth forward speed ratios are determinedutilizing the ring gear/sun gear tooth ratios of the planetary gear sets1320, 1330 and 1340. The numerical values of the sixth and seventhforward speed ratios are determined utilizing the ring gear/sun geartooth ratios of the planetary gear sets 1320 and 1330.

A powertrain 1410, shown in FIG. 15a, includes the conventional engineand torque converter 12, a planetary transmission 1414, and theconventional final drive mechanism 16. The engine and torque converterare drivingly connected with the planetary transmission 1414 through theinput shaft 17. The planetary transmission 1414 is drivingly connectedwith the final drive mechanism 16 through the output shaft 19. Theplanetary transmission 1414 includes a planetary gear arrangement 1418that has a first planetary gear set 1420, a second planetary gear set1430, and a third planetary gear set 1440.

The planetary gear set 1420 includes a sun gear member 1422, a ring gearmember 1424, and a planet carrier assembly 1426. The planet carrierassembly 1426 includes a plurality of pinion gears 1427 rotatablymounted on a carrier member 1429 and disposed in meshing relationshipwith both the sun gear member 1422 and the ring gear member 1424.

The planetary gear set 1430 includes a sun gear member 1432, a ring gearmember 1434, and a planet carrier assembly member 1436. The planetcarrier assembly member 1436 includes a plurality of pinion gears 1437rotatably mounted on a carrier member 1439 and disposed in meshingrelationship with both the sun gear member 1432 and the ring gear member1434.

The planetary gear set 1440 includes a sun gear member 1442, a ring gearmember 1444, and a planet carrier assembly member 1446. The planetcarrier assembly member 1446 includes a plurality of pinion gears 1447rotatably mounted on a carrier member 1449 and disposed in meshingrelationship with both the sun gear member 1442 and the ring gear member1444.

The planetary gear arrangement 1418 also includes sixtorque-transmitting mechanisms 1450, 1452, 1454, 1456, 1458 and 1459.The torque-transmitting mechanisms 1450, 1452, 1454, 1456 and 1458 arerotating type torque-transmitting mechanisms, commonly termed clutches.The torque-transmitting mechanism 1459 is a stationary-typetorque-transmitting mechanism, commonly termed brake or reaction clutch.

The input shaft 17 is continuously connected with the sun gear member1442, and the output shaft 19 is continuously connected with the planetcarrier assembly member 1436. The sun gear member 1422 is continuouslyconnected with the transmission housing 1460. The ring gear member 1424is continuously connected with the sun gear member 1432 and the ringgear member 1444 through the interconnecting member 1470.

The ring gear member 1424 is selectively connectable with the planetcarrier assembly member 1426 through the clutch 1450. The planet carrierassembly member 1426 is selectively connectable with the planet carrierassembly member 1436 through the clutch 1452. The planet carrierassembly member 1426 is selectively connectable with the planet carrierassembly member 1446 through the clutch 1454. The ring gear member 1434is selectively connectable with the sun gear member 1432 through theclutch 1456. The ring gear member 1434 is selectively connectable withthe sun gear member 1442 through the clutch 1458. The planet carrierassembly member 1446 is selectively connectable with the transmissionhousing 1460 through the brake 1459.

The truth table shown in FIG. 15b describes the engagement combinationsand the engagement sequence necessary to provide the reverse drive ratioand seven forward speed ratios. A sample of the numerical values for theratios is also provided in the truth table of FIG. 15b. These values aredetermined utilizing the ring gear/sun gear tooth ratios also given inFIG. 15b. The R1/S1 value is the tooth ratio for the planetary gear set1420; the R2/S2 value is the tooth ratio for the planetary gear set1430; and the R3/S3 value is the tooth ratio for the planetary gear set1440. Also given in FIG. 15b is a chart describing the step ratiosbetween the adjacent forward speed ratios and the reverse to firstforward speed ratio.

Those skilled in the art will recognize that the numerical value of thereverse speed ratio is determined utilizing the ring gear/sun gear toothratio of the planetary gear set 1440. The numerical value of the firstforward speed ratio is determined utilizing the ring gear/sun gear toothratios of the planetary gear sets 1430 and 1440. The numerical value ofthe second forward speed ratio is determined utilizing the ring gear/sungear tooth ratio of the planetary gear set 1430. The numerical value ofthe third forward speed ratio is 1. The numerical value of the fourthforward speed ratio is determined utilizing the ring gear/sun gear toothratios of the planetary gear sets 1420 and 1430. The numerical value ofthe fifth forward speed ratio is determined utilizing the ring gear/sungear tooth ratios of the planetary gear sets 1420, 1430 and 1440. Thenumerical values of the sixth and seventh forward speed ratios aredetermined utilizing the ring gear/sun gear tooth ratios of theplanetary gear sets 1420 and 1440.

A powertrain 1510, shown in FIG. 16a, includes the conventional engineand torque converter 12, a planetary transmission 1514, and theconventional final drive mechanism 16. The engine and torque converterare drivingly connected with the planetary transmission 1514 through theinput shaft 17. The planetary transmission 1514 is drivingly connectedwith the final drive mechanism 16 through the output shaft 19. Theplanetary transmission 1514 includes a planetary gear arrangement 1518that has a first planetary gear set 1520, a second planetary gear set1530, and a third planetary gear set 1540.

The planetary gear set 1520 includes a sun gear member 1522, a ring gearmember 1524, and a planet carrier assembly 1526. The planet carrierassembly 1526 includes a plurality of pinion gears 1527 rotatablymounted on a carrier member 1529 and disposed in meshing relationshipwith both the sun gear member 1522 and the ring gear member 1524.

The planetary gear set 1530 includes a sun gear member 1532, a ring gearmember 1534, and a planet carrier assembly member 1536. The planetcarrier assembly member 1536 includes a plurality of pinion gears 1537rotatably mounted on a carrier member 1539 and disposed in meshingrelationship with both the sun gear member 1532 and the ring gear member1534.

The planetary gear set 1540 includes a sun gear member 1542, a ring gearmember 1544, and a planet carrier assembly member 1546. The planetcarrier assembly member 1546 includes a plurality of pinion gears 1547and 1548 rotatably mounted on a carrier member 1549 and disposed inmeshing relationship with both the sun gear member 1542 and the ringgear member 1544.

The planetary gear arrangement 1518 also includes sixtorque-transmitting mechanisms 1550, 1552, 1554, 1556, 1558 and 1559,each of which is a rotating type torque-transmitting mechanism, commonlytermed clutch.

The input shaft 17 is continuously connected with the sun gear member1532, and the output shaft 19 is continuously connected with the planetcarrier assembly member 1546. The sun gear member 1522 is continuouslyconnected with the transmission housing 1560. The ring gear member 1524is continuously connected with the planet carrier assembly member 1536and the sun gear member 1542 through the interconnecting member 1570.

The ring gear member 1524 is selectively connectable with the planetcarrier assembly member 1526 through the clutch 1550. The planet carrierassembly member 1526 is selectively connectable with the sun gear member1532 through the clutch 1552. The planet carrier assembly member 1526 isselectively connectable with the ring gear member 1534 through theclutch 1554. The planet carrier assembly member 1546 is selectivelyconnectable with the sun gear member 1542 through the clutch 1556. Thering gear member 1534 is selectively connectable with the planet carrierassembly member 1546 through the clutch 1558. The ring gear member 1534is selectively connectable with the ring gear member 1544 through theclutch 1559.

The truth table shown in FIG. 16b describes the engagement combinationsand the engagement sequence necessary to provide the reverse drive ratioand the seven forward speed ratios. A sample of the numerical values forthe ratios is also provided in the truth table of FIG. 16b. These valuesare determined utilizing the ring gear/sun gear tooth ratios also givenin FIG. 16b. The R1/S1 value is the tooth ratio for the planetary gearset 1520; the R2/S2 value is the tooth ratio for the planetary gear set1530; and the R3/S3 value is the tooth ratio for the planetary gear set1540. Also given in FIG. 16b is a chart describing the step ratiosbetween the adjacent forward speed ratios and the reverse to firstforward speed ratio.

Those skilled in the art will recognize that the numerical value of thereverse speed ratio is determined utilizing the ring gear/sun gear toothratios of the planetary gear sets 1530 and 1540. The numerical values ofthe first and seventh forward speed ratios are determined utilizing thering gear/sun gear tooth ratios of the planetary gear sets 1520, 1530and 1540. The numerical values of the second, third and sixth forwardspeed ratios are determined utilizing the ring gear/sun gear toothratios of the planetary gear sets 1520 and 1530. The numerical value ofthe fourth forward speed ratio is 1. The numerical value of the fifthforward speed ratio is determined utilizing the ring gear/sun gear toothratio of the planetary gear set 1520.

A powertrain 1610, shown in FIG. 17a, includes the conventional engineand torque converter 12, a planetary transmission 1614, and theconventional final drive mechanism 16. The engine and torque converterare drivingly connected with the planetary transmission 1614 through theinput shaft 17. The planetary transmission 1614 is drivingly connectedwith the final drive mechanism 16 through the output shaft 19. Theplanetary transmission 1614 includes a planetary gear arrangement 1618that has a first planetary gear set 1620, a second planetary gear set1630, and a third planetary gear set 1640.

The planetary gear set 1620 includes a sun gear member 1622, a ring gearmember 1624, and a planet carrier assembly 1626. The planet carrierassembly 1626 includes a plurality of pinion gears 1627 rotatablymounted on a carrier member 1629 and disposed in meshing relationshipwith both the sun gear member 1622 and the ring gear member 1624.

The planetary gear set 1630 includes a sun gear member 1632, a ring gearmember 1634, and a planet carrier assembly member 1636. The planetcarrier assembly member 1636 includes a plurality of pinion gears 1637rotatably mounted on a carrier member 1639 and disposed in meshingrelationship with both the sun gear member 1632 and the ring gear member1634.

The planetary gear set 1640 includes a sun gear member 1642, a ring gearmember 1644, and a planet carrier assembly member 1646. The planetcarrier assembly member 1646 includes a plurality of pinion gears 1647rotatably mounted on a carrier member 1649 and disposed in meshingrelationship with both the sun gear member 1642 and the ring gear member1644.

The planetary gear arrangement 1618 also includes sixtorque-transmitting mechanisms 1650, 1652, 1654, 1656, 1658 and 1659,each of which is a rotating-type torque-transmitting mechanism, commonlytermed clutch.

The input shaft 17 is continuously connected with the sun gear member1632, and the output shaft 19 is continuously connected with the ringgear member 1644. The sun gear member 1622 is continuously connectedwith the transmission housing 1660. The ring gear member 1624 iscontinuously connected with the planet carrier assembly members 1636 and1646 through the interconnecting member 1670.

The ring gear member 1624 is selectively connectable with the planetcarrier assembly member 1626 through the clutch 1650. The planet carrierassembly member 1626 is selectively connectable with the sun gear member1632 through the clutch 1652. The planet carrier assembly member 1626 isselectively connectable with the ring gear member 1634 through theclutch 1654. The ring gear member 1644 is selectively connectable withthe planet carrier assembly member 1646 through the clutch 1656. The sungear member 1632 is selectively connectable with the sun gear member1642 through the clutch 1658. The ring gear member 1634 is selectivelyconnectable with the ring gear member 1644 through the clutch 1659.

The truth table shown in FIG. 17b describes the engagement combinationsand the engagement sequence necessary to provide the reverse drive ratioand the seven forward speed ratios. A sample of the numerical values forthe ratios is also provided in the truth table of FIG. 17b. These valuesare determined utilizing the ring gear/sun gear tooth ratios also givenin FIG. 17b. The R1/S1 value is the tooth ratio for the planetary gearset 1620; the R2/S2 value is the tooth ratio for the planetary gear set1630; and the R3/S3 value is the tooth ratio for the planetary gear set1640. Also given in FIG. 17b is a chart describing the step ratiosbetween the adjacent forward speed ratios and the reverse to firstforward speed ratio.

Those skilled in the art will recognize that the numerical value of thereverse speed ratio is determined utilizing the ring gear/sun gear toothratio of the planetary gear set 1640. The numerical value of the firstforward speed ratio is determined utilizing the ring gear/sun gear toothratios of the planetary gear sets 1620, 1630 and 1640. The numericalvalues of the second, third and sixth forward speed ratios aredetermined utilizing the ring gear/sun gear tooth ratios of theplanetary gear sets 1620 and 1630. The numerical value of the fourthforward speed ratio is 1. The numerical value of the fifth forward speedratio is determined utilizing the ring gear/sun gear tooth ratio of theplanetary gear set 1620. The numerical value of the seventh forwardspeed ratio is determined utilizing the ring gear/sun gear tooth ratiosof the planetary gear sets 1620 and 1640.

A powertrain 1710, shown in FIG. 18a, includes the conventional engineand torque converter 12, a planetary transmission 1714, and theconventional final drive mechanism 16. The engine and torque converterare drivingly connected with the planetary transmission 1714 through theinput shaft 17. The planetary transmission 1714 is drivingly connectedwith the final drive mechanism 16 through the output shaft 19. Theplanetary transmission 1714 includes a planetary gear arrangement 1718that has a first planetary gear set 1720, a second planetary gear set1730, and a third planetary gear set 1740.

The planetary gear set 1720 includes a sun gear member 1722, a ring gearmember 1724, and a planet carrier assembly 1726. The planet carrierassembly 1726 includes a plurality of pinion gears 1727 rotatablymounted on a carrier member 1729 and disposed in meshing relationshipwith both the sun gear member 1722 and the ring gear member 1724.

The planetary gear set 1730 includes a sun gear member 1732, a ring gearmember 1734, and a planet carrier assembly member 1736. The planetcarrier assembly member 1736 includes a plurality of pinion gears 1737rotatably mounted on a carrier member 1739 and disposed in meshingrelationship with both the sun gear member 1732 and the ring gear member1734.

The planetary gear set 1740 includes a sun gear member 1742, a ring gearmember 1744, and a planet carrier assembly member 1746. The planetcarrier assembly member 1746 includes a plurality of pinion gears 1747rotatably mounted on a carrier member 1749 and disposed in meshingrelationship with both the sun gear member 1742 and the ring gear member1744.

The planetary gear arrangement 1718 also includes sixtorque-transmitting mechanisms 1750, 1752, 1754, 1756, 1758 and 1759,each of which is a rotating-type torque-transmitting mechanism, commonlytermed clutch.

The input shaft 17 is continuously connected with the sun gear member1742, and the output shaft 19 is continuously connected with the planetcarrier assembly member 1736. The ring gear member 1724 is continuouslyconnected with the transmission housing 1760. The sun gear member 1722is continuously connected with the sun gear member 1732 and the ringgear member 1744 through the interconnecting member 1770.

The planet carrier assembly member 1726 is selectively connectable withthe sun gear member 1722 through the clutch 1750. The planet carrierassembly member 1726 is selectively connectable with the planet carrierassembly member 1736 through the clutch 1752. The planet carrierassembly member 1726 is selectively connectable with the sun gear member1742 through the clutch 1754. The planet carrier assembly member 1736 isselectively connectable with the planet carrier assembly member 1746through the clutch 1756. The ring gear member 1734 is selectivelyconnectable with the planet carrier assembly member 1746 through theclutch 1758. The ring gear member 1734 is selectively connectable withthe sun gear member 1742 through the clutch 1759.

The truth table shown in FIG. 18b describes the engagement combinationsand the engagement sequence necessary to provide the reverse drive ratioand seven forward speed ratios. A sample of the numerical values for theratios is also provided in the truth table of FIG. 18b. These values aredetermined utilizing the ring gear/sun gear tooth ratios also given1720; the R2/S2 value is the tooth ratio for the planetary gear set1730; and the R3/S3 value is the tooth ratio for the planetary gear set1740. Also given in FIG. 18b is a chart describing the step ratiosbetween the adjacent forward speed ratios and the reverse to firstforward speed ratio.

Those skilled in the art will recognize that the numerical values of thereverse and sixth forward speed ratios are determined utilizing the ringgear/sun gear tooth ratios of the planetary gear sets 1720 and 1740. Thenumerical value of the first forward speed ratio is determined utilizingthe ring gear/sun gear tooth ratios of the planetary gear sets 1730 and1740. The numerical value of the second forward speed ratio isdetermined utilizing the ring gear/sun gear tooth ratio of the planetarygear set 1740. The numerical value of the third forward speed ratio isdetermined utilizing the ring gear/sun gear tooth ratio of the planetarygear set 1730. The numerical value of the fourth forward speed ratiois 1. The numerical value of the fifth forward speed ratio is determinedutilizing the ring gear/sun gear tooth ratios of the planetary gear sets1720 and 1730. The numerical value of the seventh forward speed ratio isdetermined utilizing the ring gear/sun gear tooth ratios of theplanetary gear sets 1720, 1730 and 1740.

While the best modes for carrying out the invention have been describedin detail, those familiar with the art to which this invention relateswill recognize various alternative designs and embodiments forpracticing the invention within the scope of the appended claims.

What is claimed is:
 1. A multi-speed transmission comprising: an inputshaft; an output shaft; first, second and third planetary gear sets eachhaving first, second and third members; said input shaft beingcontinuously interconnected with a member of said planetary gear sets,and said output shaft being continuously interconnected with anothermember of said planetary gear sets; an interconnecting membercontinuously interconnecting said first member of said first planetarygear set with said first member of said second planetary gear set andsaid first member of said third planetary gear set; said second memberof said first planetary gear set being continuously connected with astationary member; a first torque-transmitting mechanism selectivelyinterconnecting said third member of said first planetary gear set witha member of said second or third planetary gear set; a secondtorque-transmitting mechanism selectively interconnecting a said secondmember of said second planetary gear set with a member of said thirdplanetary gear set; a third torque-transmitting mechanism selectivelyinterconnecting said second member of said third planetary gear set witha member of said first or second planetary gear set; a fourthtorque-transmitting mechanism selectively interconnecting a member ofsaid first or second planetary gear set with another member of saidfist, second or third planetary gear set or with said stationary member;a fifth torque-transmitting mechanism selectively interconnecting amember of said second planetary gear set with another member of saidplanetary gear sets or said stationary member; and a sixthtorque-transmitting mechanism selectively interconnecting a member ofthe third planetary gear set with another member of said first, secondor third planetary gear set or said stationary member; saidtorque-transmitting mechanisms being engaged in combinations of two toestablish at least seven forward speed ratios and at least one reversespeed ratio between said input shaft and said output shaft.
 2. Thetransmission defined in claim 1, wherein said first, second, third,fourth, fifth and sixth torque-transmitting mechanisms compriseclutches.
 3. The transmission defined in claim 1, wherein said first,second, third, fourth and fifth torque-transmitting mechanisms compriseclutches, and said sixth torque-transmitting mechanism comprises abrake.
 4. The transmission defined in claim 1, wherein said first,second and third torque-transmitting mechanisms comprise clutches, andsaid fourth, fifth and sixth torque-transmitting mechanisms comprisebrakes.
 5. The transmission defined in claim 1, wherein said first,second, third and fourth torque-transmitting mechanisms compriseclutches, and said fifth and sixth torque-transmitting mechanismscomprise brakes.
 6. The transmission defined in claim 1, wherein planetcarrier assembly members of each of said planetary gear sets aresingle-pinion carriers.
 7. The transmission defined in claim 1, whereinat least one planet carrier assembly member of said planetary gear setsis a double-pinion carrier.
 8. A multi-speed transmission comprising: aninput shaft; an output shaft; a planetary gear arrangement having first,second and third planetary gear sets, each planetary gear set havingfirst, second and third members; said input shaft being continuouslyinterconnected with a member of said planetary gear sets, and saidoutput shaft being continuously interconnected with another member ofsaid planetary gear sets; an interconnecting member continuouslyinterconnecting said first member of said first planetary gear set withsaid first member of said second planetary gear set and said firstmember of said third planetary gear set; said second member of saidfirst planetary gear set being continuously connected with a stationarymember; and six torque-transmitting mechanisms for selectivelyinterconnecting said members to establish combinations of members joinedfor common rotation and said six torque-transmitting mechanisms beingengaged in combinations of two to establish at least seven forward speedratios and one reverse speed ratio between said input shaft and saidoutput shaft.
 9. The transmission defined in claim 8, wherein a first ofsaid six torque-transmitting mechanisms is operable for selectivelyinterconnecting said third member of said first planetary gear set witha member of said second or third planetary gear set.
 10. Thetransmission defined in claim 8, wherein a second of said sixtorque-transmitting mechanisms is operable for selectivelyinterconnecting said second member of said second planetary gear setwith a member of said third planetary gear set.
 11. The transmissiondefined in claim 8, wherein a third of said six torque-transmittingmechanisms is operable for selectively interconnecting said secondmember of said third planetary gear set with a member of said first orsecond planetary gear set.
 12. The transmission defined in claim 8,wherein a fourth of said six torque-transmitting mechanisms isselectively operable for interconnecting a member of said first orsecond planetary gear set with another member of said first, second orthird planetary gear set.
 13. The transmission defined in claim 8,wherein a fourth of said six torque-transmitting mechanisms isselectively operable for interconnecting a member of said firstplanetary gear set with said stationary member.
 14. The transmissiondefined in claim 8, wherein a fifth of said six torque-transmittingmechanisms is selectively operable for interconnecting a member of saidsecond planetary gear set with another member of said first, second orthird planetary gear set.
 15. The transmission defined in claim 8,wherein a fifth of said six torque-transmitting mechanisms isselectively operable for interconnecting a member of said secondplanetary gear set with said stationary member.
 16. The transmissiondefined in claim 8, wherein a sixth of said six torque-transmittingmechanisms is selectively operable for interconnecting a member of saidthird planetary gear set with another member of said first, second orthird planetary gear set.
 17. The transmission defined in claim 8,wherein a sixth of said six torque-transmitting mechanisms isselectively operable for interconnecting a member of said thirdplanetary gear set with said stationary member.
 18. The transmissiondefined in claim 8, wherein planet carrier assembly members of each ofsaid planetary gear sets are single-pinion carriers.
 19. Thetransmission in claim 8, wherein at least one planet carrier assemblymember of said planetary gear sets is a double-pinion carrier.